Editing Sweat gland

{{Short description|Small sweat-producing tubular skin structures}}
{{Infobox anatomy
| Name        = Sweat gland
| Latin       = glandula sudorifera<ref name=th>{{Terminologia Anatomica|A16.0.00.029}}</ref><ref name=grayanat/>
| Greek       = 
| Image       = Human_skin_structure.svg
| Caption     = A cross-section of the human skin, with the sweat gland labeled at the bottom
| Width       = 
| Image2      = 
| Caption2    = 
| Precursor   = Ectoderm<ref name=neas />
| System      = Integumentary<ref name=neas />
| Artery      = 
| Vein        = 
| Nerve       = Eccrine: cholinergic sympathetic nerves{{sfn|Krstic|2004|p=464}}<br />Apocrine: adrenergic nerves{{sfn|Krstic|2004|p=466}}
| Lymph       = 
}}
<!--PARAGRAPH: This e uses {{sfn}} (shortened footnotes) instead of {{rp}} to specify page numbers, using {{rp}} too many times takes up too much space in the article text and makes it harder to read.-->
'''Sweat glands''', also known as '''sudoriferous''' or '''sudoriparous glands''', {{etymology|la|sudor|sweat}},<ref name=oxford>{{cite encyclopedia|title=sudoriferous|encyclopedia=The New Oxford American Dictionary|edition=2nd}}</ref><ref name=saunders03 /> are small tubular structures of the [[skin]] that produce [[sweat]]. Sweat glands are a type of [[exocrine gland]], which are glands that produce and secrete substances onto an [[epithelial]] surface by way of a [[duct (anatomy)|duct]]. There are two main types of sweat glands that differ in their structure, function, secretory product, mechanism of excretion, anatomic distribution, and distribution across species:
* [[Eccrine sweat gland]]s are distributed almost all over the human body, in varying densities, with the highest density in palms and soles, then on the head, but much less on the trunk and the extremities. Their water-based secretion represents a primary form of [[thermoregulation|cooling]] in humans.{{sfn|Kurosumi|Shibasaki|Ito|1984|p=255}}
* [[Apocrine sweat gland]]s are mostly limited to the [[axilla|axillae (armpits)]] and [[perineum|perineal area]] in humans.{{sfn|Kurosumi|Shibasaki|Ito|1984|p=255}} They are not significant for cooling in humans, but are the sole effective sweat glands in hoofed animals, such as the [[camel]]s, [[donkey]]s, [[horse]]s, and [[cattle]].{{sfn|Folk|Semken|1991|p=181}}<ref name=bullard70 />{{sfn|Sørensen|Prasad|1973|p=173}}

[[Ceruminous glands]] (which produce ear wax), [[mammary glands]] (which produce [[milk]]), and [[ciliary glands]] in the eyelids are modified apocrine sweat glands.<ref name="grayanat" /><ref name="Ackerman2005" />

==Structure==
[[File:Gray946.png|thumb|Body of a sweat gland cut in various directions]]
Generally, sweat glands consist of a secretory unit that produces sweat, and a duct that carries the sweat away. The ''secretory coil ''or base, is set deep in the lower [[dermis]] and [[hypodermis]], and the entire gland is surrounded by [[adipose tissue]].<ref name=grayanat /><ref name=caceci />{{sfn|Kurosumi|Shibasaki|Ito|1984|p=255}} In both sweat gland types, the secretory coils are surrounded by contractile myoepithelial cells that function to facilitate excretion of secretory product.{{sfn|Kurosumi|Shibasaki|Ito|1984|p = 256}}{{sfn|Eroschenko|2008|pp = 222, 226, 228}} The secretory activities of the gland cells and the contractions of [[myoepithelial cells]] are controlled by both the autonomic nervous system and by the circulating hormones. The distal or apical part of the duct that opens to the skin's surface is known as the ''acrosyringium''.<ref name="Bolognia et al">{{Cite book|title = Dermatology. Structure and Function of Eccrine, Apocrine and Sebaceous Glands|last = Bolognia, Jorizzo, Schaffer|year = 2012|isbn = 978-0723435716|pages = 539–544|edition = 3rd}}</ref>

Each sweat gland receives several [[nerve fibers]] that branch out into bands of one or more [[axons]] and encircle the individual tubules of the secretory coil. [[Capillaries]] are also interwoven among sweat tubules.<ref name="kennedy94" />

{| class="wikitable"
|+ Differences Between Eccrine & Apocrine Sweat Glands
! &nbsp; !! Eccrine Glands !! Apocrine Glands
|-
| Overall diameter of secretory coil
| 500-700 [[μm]]
| 800&nbsp;μm
|-
| Diameter of individual secretory tubule
| 30-40&nbsp;μm
| 80-100&nbsp;μm{{sfn|Wilke|Martin|Terstegen|Biel|2007|pp=173, 175}}
|-
| Composition of secretory epithelium
| single layer, mixed clear cells & dark cells
| single layer columnar cells<ref name="Bolognia et al"/>
|-
| Composition of ductal epithelium
| two or more layers of cuboidal cells
| double layer of cuboidal cells{{sfn|Eroschenko|2008|p=228}}
|-
| Duct opens to
| skin surface
| hair follicle, sometimes nearby skin surface
|}

==Distribution==
[[File:Fingerprt.jpg|thumb|Human sweat gland pores on the ridges of a finger pad]]
The number of active sweat glands varies greatly among different people, though comparisons between different areas (ex. axillae vs. groin) show the same directional changes (certain areas always have more active sweat glands while others always have fewer).{{sfn|Randall|2012}} According to [[Henry Gray]]'s estimates, the palm has around 370 sweat glands per cm<sup>2</sup>; the back of the hand has 200 per cm<sup>2</sup>; the forehead has 175 per cm<sup>2</sup>; the breast, abdomen, and forearm have 155 per cm<sup>2</sup>; and the back and legs have 60–80 per cm<sup>2</sup>.<ref name=grayanat />

In the finger pads, sweat glands pores are somewhat irregularly spaced on the [[Dermal papillae|epidermal ridges]]. There are no pores between the ridges, though sweat tends to spill into them.{{sfn|Randall|2012}} The thick epidermis of the palms and soles causes the sweat glands to become spirally coiled.<ref name=grayanat />

===Other animals===

Non-primate mammals have eccrine sweat glands only on the palms and soles. Apocrine glands cover the rest of the body, though they are not as effective as humans' in temperature regulation (with the exception of [[horse]]s').{{sfn|Kurosumi|Shibasaki|Ito|1984|p=255}} [[Prosimian]]s have a 1:20 ratio of follicles with apocrine glands versus follicles without.{{sfn|Folk|Semken|1991|p=182}} They have eccrine glands between hairs over most of their body (while humans have them between the hairs on their [[scalp]]).{{sfn|Folk|Semken|1991|p=181}}

The overall distribution of sweat glands varies among primates: the [[rhesus monkey|rhesus]] and [[patas monkey]]s have them on the chest; the [[squirrel monkey]] has them only on the palms and soles; and the [[stump-tailed macaque]], [[Japanese monkey]], and [[baboon]] have them over the entire body.{{sfn|Folk|Semken|1991|p=183}}

Domestic animals{{Which|date = March 2013}} have [[apocrine glands]] at the base of each hair follicle, but [[eccrine glands]] only in foot pads and snout. Their apocrine glands, like those in humans, produce an odorless oily milky secretion evolved not to evaporate and cool but rather coat and stick to hair so odor-causing bacteria can grow on it.<ref name="merck" /> Eccrine glands on their foot pads, like those on palms and soles of humans, did not evolve to cool either but rather increase friction and enhance grip.

Dogs and cats have apocrine glands that are specialized in both structure and function located at the eyelids ([[Moll's glands]]), ears ([[ceruminous gland]]s), [[anal sac]], [[clitoral hood]], and [[perineum|circumanal area]].<ref name=slatter03 />

== History ==
The pores of eccrine sweat pores were first identified by the Italian physiologist [[Marcello Malpighi]]. Sweat glands themselves were first discovered by the Czech physiologist, [[Jan Evangelista Purkyně|Johannes Purkinjé]] in 1833. The differing densities of sweat glands in different body regions was first investigated in 1844 by the German anatomist Karl Krause. Sweat glands were first separated into kinds by the French histologist [[Louis-Antoine Ranvier]], who separated them in 1887 regarding their type of secretion into [[Holocrine|holocrine glands]] ([[Sebaceous gland|sebaceous glands]]) and the [[Merocrine|merocrine glands]] (sweat glands), the latter were then in 1917 divided into apocrine and eccrine sweat glands. In 1987, apoeccrine glands were identified.<ref name="Taylor Machado-Moreira 2013 p.">{{cite journal |last1=Taylor |first1=Nigel AS |last2=Machado-Moreira |first2=Christiano A |date=2013 |title=Regional variations in transepidermal water loss, eccrine sweat gland density, sweat secretion rates and electrolyte composition in resting and exercising humans |journal=Extreme Physiology & Medicine |volume=2 |issue=1 |page= 4|doi=10.1186/2046-7648-2-4 |issn=2046-7648 |pmc=3710196 |pmid=23849497 |doi-access=free }}</ref>

==Types==

===Eccrine===
{{main|Eccrine sweat gland}}
Eccrine sweat glands are everywhere except the lips, [[ear canal]], [[foreskin]], [[glans penis]], [[labia minora]], [[clitoral hood]], and [[clitoris]]. They are ten times smaller than apocrine sweat glands, do not extend as deeply into the dermis, and excrete directly onto the surface of the skin.{{sfn|Kurosumi|Shibasaki|Ito|1984|p=255}}{{sfn|Krstic|2004|p=466}}<ref name=spearman73>{{cite book| publisher = CUP Archive| isbn = 9780521200486| volume = 3| last = Spearman| first = Richard Ian Campbell| title = The Integument: A Textbook For Skin Biology| series = Biological Structure and Function Books| year = 1973| page = [https://archive.org/details/integumenttextbo00spea/page/135 135]| url = https://archive.org/details/integumenttextbo00spea/page/135}}</ref>{{sfn|Krstic|2004|p=464}} The proportion of eccrine glands decreases with age.{{sfn|Wilke|Martin|Terstegen|Biel|2007|pp=175–176}}

The clear secretion produced by eccrine sweat glands is termed [[sweat]] or ''sensible perspiration''. Sweat is mostly water, but it does contain some [[electrolyte]]s, since it is derived from [[blood plasma]]. The presence of [[sodium chloride]] gives sweat a salty taste.

The total volume of sweat produced depends on the number of functional glands and the size of the surface opening. The degree of secretory activity is regulated by neural and hormonal mechanisms (men sweat more than women). When all of the eccrine sweat glands are working at maximum capacity, the rate of perspiration for a human being may exceed three liters per hour,<ref>{{cite book|first1=Cleveland P. Jr.|last1=Hickman|first2=Larry S.|last2=Roberts|first3=Allan|last3=Larson|title=Integrated principles of zoology|date=April 2003|publisher=McGraw-Hill|location=Boston|isbn=9780072439403|edition=12th|page=[https://archive.org/details/isbn_9780072930283/page/634 634]|url=https://archive.org/details/isbn_9780072930283/page/634}}</ref> and dangerous losses of fluids and electrolytes can occur.

Eccrine glands have three primary functions:
* Thermoregulation: sweat (through [[evaporation]] and evaporative heat loss) can lead to cooling of the surface of the skin and a reduction of body temperature.{{sfn|Wilke|Martin|Terstegen|Biel|2007|p=170}}
* Excretion: eccrine sweat gland secretion can also provide a significant excretory route for water and electrolytes.{{sfn|Romich|2009|p=203}}
* Protection: eccrine sweat gland secretion aids in preserving the skin's [[acid mantle]], which helps protect the skin from colonization from bacteria and other pathogenic organisms.<ref>{{cite book | last=Marples|first= Mary J. | title=The ecology of the human skin | year=1965|publisher= Thomas | ol=5915977M|isbn=9780398012182}}</ref>

===Apocrine===
{{main|Apocrine sweat gland}}

Apocrine sweat glands are found in the armpit, [[areola]] (around the nipples), perineum (between the anus and genitals), in the ear, and the eyelids. The secretory portion is larger than that of eccrine glands (making them larger overall). Rather than opening directly onto the surface of the skin, apocrine glands secrete sweat into the pilary canal of the [[hair follicle]].{{sfn|Kurosumi|Shibasaki|Ito|1984|p=255}}

Before puberty, the apocrine sweat glands are inactive;<ref name=mosby /> [[Puberty#Major hormones|hormonal changes in puberty]] cause the glands to increase in size and begin functioning.<ref name=braunfalco>{{cite book| publisher = Springer Berlin Heidelberg| isbn = 978-3-642-97933-0| pages = 1083–1086| last1 = Braun-Falco| first1 = Otto| first2 = Gerd|last2= Plewig|first3=Helmut H.|last3= Wolff|first4=Walter H. C. |last4=Burgdorf| title = Dermatology| chapter = Diseases of the Apocrine Sweat Glands| date = 1 January 2000}}</ref> The substance secreted is thicker than eccrine sweat and provides nutrients for bacteria on the skin: the bacteria's decomposition of sweat is what creates the acrid odor.<ref name=dorlands /> Apocrine sweat glands are most active in times of stress and sexual excitement.<ref name=americanheritage />

In mammals (including humans), apocrine sweat contains [[pheromone]]-like compounds to attract other organisms within their species. Study of human sweat has revealed differences between men and women in apocrine secretions and bacteria.<ref>{{cite web| last1 = Currie| first1 = Ariel| first2 = Hank| last2 = Coshnear| first3 = Mila| last3 = Quinn| first4 = Logan| last4 = Sand| publisher = Macalaster College| title = Human Pheromones| access-date = 6 June 2013| url = http://www.macalester.edu/psychology/whathap/UBNRP/pheromone10/human%20pheromones.html| archive-url = https://web.archive.org/web/20130512060404/http://www.macalester.edu/psychology/whathap/UBNRP/pheromone10/human%20pheromones.html| archive-date = 12 May 2013| url-status = dead}}</ref>

===Apoeccrine===
Some human sweat glands cannot be classified as either apocrine or eccrine, having characteristics of both; such glands are termed ''apoeccrine''.{{sfn|Wilke|Martin|Terstegen|Biel|2007|p=171}} They are larger than eccrine glands, but smaller than apocrine glands.<ref>{{cite book|editor-last=Cooper|editor-first=Grant|title=Therapeutic Uses of Botulinum Toxin|url=https://archive.org/details/therapeuticusesb00coop_467|url-access=limited|year=2007|publisher=Humana Press|location=Totowa, N.J.|isbn=9781597452472|page=[https://archive.org/details/therapeuticusesb00coop_467/page/n157 155]}}</ref> Their secretory portion has a narrow portion similar to secretory coils in eccrine glands as well as a wide section reminiscent of apocrine glands.<ref>{{cite book | publisher=KARGER | isbn=978-3-8055-7306-1 | volume=30 | pages=1–9 |editor1=Kreyden, O.P. |editor2=Burg, G. | last=Böni | first=R. |author2=Groscurth, P. | title=Current Problems in Dermatology | chapter=Anatomy of Sweat Glands | location=Basel | year=2002 | chapter-url=http://www.karger.com/Article/PDF/60678}}</ref>

Apoeccrine glands, found in the armpits and perianal region, have ducts opening onto the skin surface.<ref>{{cite book | publisher=Karger Publishers | isbn=978-3805573061 | last=Kreyden | first=Oliver Philip |author2=Böni, Roland Emil |author3=Burg, Günter | title=Hyperhidrosis and Botulinum Toxin in Dermatology: 18 Tables | year= 2002|page=8}}</ref> They are presumed to have developed in puberty from the eccrine glands,{{sfn|Wilke|Martin|Terstegen|Biel|2007|p=175}} and can comprise up to 50% of all axillary glands. Apoeccrine glands secrete more sweat than both eccrine and apocrine glands, thus playing a large role in axillary sweating.{{sfn|Wilke|Martin|Terstegen|Biel|2007|p=176}} Apoeccrine glands are sensitive to cholinergic activity, though they can also be activated via adrenergic stimulation.{{sfn|Wilke|Martin|Terstegen|Biel|2007|p=171}} Like eccrine glands, they continuously secrete a thin, watery sweat.{{sfn|Wilke|Martin|Terstegen|Biel|2007|p=176}}

===Others===

Specialized sweat glands, including the [[ceruminous gland]]s, [[mammary gland]]s, ciliary glands of the eyelids, and sweat glands of the [[nasal vestibule|nasal vestibulum]], are modified apocrine glands.<ref name=hogin06>{{cite book| publisher = Sterling Publishing Company, Inc.| isbn = 9781402737886| last = McMurtrie| first = Hogin| title = McMurtrie's Human Anatomy Coloring Book: A Systemic Approach to the Study of the Human Body: Thirteen Systems| date = 28 November 2006|page=430}}</ref>{{sfn|Krstic|2004|p=466}} Ceruminous glands are near the ear canals, and produce cerumen (earwax) that mixes with the oil secreted from [[sebaceous glands]].{{sfn|Romich|2009|p=206}}<ref name=hogin06 /> Mammary glands use apocrine secretion to produce milk.<ref name=vanlommel />

==Sweat==
Sweat glands are used to regulate temperature and remove waste by secreting water, [[sodium salt]]s, and [[nitrogenous waste]] (such as urea) onto the skin surface.{{sfn|Romich|2009|p=203}}{{sfn|Eroschenko|2008|p=215}} The main electrolytes of sweat are [[sodium]] and [[chloride]],<ref>{{cite book | publisher=Elsevier Health Sciences | isbn=978-1416024439 | last=Frontera | first=Walter R. | title=Clinical Sports Medicine: Medical Management and Rehabilitation | year= 2007|page=29}}</ref> though the amount is small enough to make sweat [[hypotonic]] at the skin surface.{{sfn|Slegers|1964|p=271}} Eccrine sweat is clear, odorless, and is composed of 98–99% water; it also contains [[NaCl]], [[fatty acids]], [[lactic acid]], [[citric acid]], [[ascorbic acid]], urea, and [[uric acid]]. Its [[pH]] ranges from 4 to 6.8.<ref name=draelos10 /> On the other hand, the apocrine sweat has a pH of 6 to 7.5; it contains water, proteins, carbohydrate waste material, lipids, and [[steroid]]s. The sweat is oily, cloudy, viscous, and originally odorless;<ref name=draelos10 /> it gains odor upon decomposition by bacteria. Because both apocrine glands and sebaceous glands open into the hair follicle, apocrine sweat is mixed with [[sebum]].{{sfn|Wilke|Martin|Terstegen|Biel|2007|p=175}}

===Mechanism===
[[File:Apocrine.jpg|thumbnail|In apocrine secretion (pictured), portions of the cell are pinched off and later disintegrate.]]
Both apocrine and eccrine sweat glands use [[merocrine|merocrine secretion]], where [[vesicle (biology)|vesicle]]s in the gland release sweat via [[exocytosis]], leaving the entire cell intact.{{sfn|Wilke|Martin|Terstegen|Biel|2007|p=171}}<ref name=saunders03 /> It was originally thought that apocrine sweat glands use apocrine secretion due to histological artifacts resembling "blebs" on the cell surface, however, recent electron micrographs indicate that the cells use merocrine secretion.<ref>{{cite web |url=http://medcell.med.yale.edu/histology/skin_lab/apocrine_sweat_glands.php |website=Histology@Yale |access-date=23 March 2019 |title=Apocrine Sweat Glands |archive-date=7 August 2020 |archive-url=https://web.archive.org/web/20200807203447/http://medcell.med.yale.edu/histology/skin_lab/apocrine_sweat_glands.php |url-status=dead }}</ref>
In both apocrine and eccrine sweat glands, the sweat is originally produced in the gland's coil, where it is [[isotonicity|isotonic]] with the [[blood plasma]] there.{{sfn|Slegers|1964|p=265}} When the rate of sweating is low, salt is conserved and reabsorbed by the gland's duct; high sweat rates, on the other hand, lead to less salt reabsorption and allow more water to evaporate on the skin (via [[osmosis]]) to increase [[evaporative cooling]].{{sfn|Slegers|1964|p=272}}

Secretion of sweat occurs when the [[myoepithelial cell]] cells surrounding the secretory glands contract.{{sfn|Eroschenko|2008|p=228}} Eccrine sweat increases the rate of bacterial growth and [[Volatilized|volatilizes]] the odor compounds of apocrine sweat, strengthening the latter's acrid smell.{{sfn|Tsai|2006|p=497}}

Normally, only a certain number of sweat glands are actively producing sweat. When stimuli call for more sweating, more sweat glands are activated, with each then producing more sweat.{{sfn|Shibasaki|Wilson|Crandall|2006|p=1694}}<ref name=randall46 />

===Stimuli===

====Thermal====
Both eccrine and apocrine sweat glands participate in thermoregulatory sweating,{{sfn|Folk|Semken|1991|p=180}} which is directly controlled by the [[hypothalamus]]. Thermal sweating is stimulated by a combination of internal body temperature and mean skin temperature.{{sfn|Wilke|Martin|Terstegen|Biel|2007|p=170}} In eccrine sweat glands, stimulation occurs via activation by [[acetylcholine]], which binds to the gland's [[muscarinic receptors]].{{sfn|Shibasaki|Wilson|Crandall|2006|p=1693}}

====Emotional====
Emotional sweating is stimulated by stress, anxiety, fear, and pain; it is independent of ambient temperature. Acetylcholine acts on the eccrine glands and [[adrenaline]] acts on both eccrine and apocrine glands to produce sweat.{{sfn|Wilke|Martin|Terstegen|Biel|2007|p=171}} Emotional sweating can occur anywhere, though it is most evident on the palms, soles of the feet, and axillary regions.{{sfn|Wilke|Martin|Terstegen|Biel|2007|p=170}} Sweating on the palms and soles is thought to have evolved as a fleeing reaction in mammals: it increases friction and prevents slipping when running or climbing in stressful situations.{{sfn|Folk|Semken|1991|p=180}}

====Gustatory====
Gustatory sweating refers to thermal sweating induced by the ingestion of food. The increase in metabolism caused by ingestion raises body temperature, leading to thermal sweating. Hot and spicy foods also lead to mild gustatory sweating in the face, scalp and neck: [[capsaicin]] (the compound that makes spicy food taste "hot"), binds to [[Sensory receptor|receptor]]s in the mouth that detect warmth. The increased stimulation of such receptors induces a thermoregulatory response.{{sfn|Wilke|Martin|Terstegen|Biel|2007|p=171}}

===Antiperspirant===
Unlike [[deodorant]], which simply reduces axillary odor without affecting body functions, [[antiperspirant]] reduces both eccrine and apocrine sweating.{{sfn|Kasture|Gokhal|Parakh|Paradkar|2008|p=15.15}}<ref name=draelos10 /> Antiperspirants, which are classified as drugs, cause proteins to precipitate and mechanically block eccrine (and sometimes apocrine) sweat ducts.{{sfn|Kasture|Gokhal|Parakh|Paradkar|2008|p=15.14}} The metal salts found in antiperspirants alters the [[keratin]] [[fibril]]s in the ducts; the ducts then close and form a "horny plug". The main active ingredients in modern antiperspirants are [[aluminum chloride]], [[aluminum chlorohydrate]], aluminum zirconium chlorohydrate, and buffered [[aluminum sulfate]].<ref name=draelos10 />

On apocrine glands, antiperspirants also contain [[antibacterial]] agents such as [[trichlorocarbanilide]], [[hexamethylene tetramine]], and [[zinc ricinoleate]].<ref name=britannica-skindis />{{sfn|Kasture|Gokhal|Parakh|Paradkar|2008|p=15.16}} The salts are dissolved in [[ethanol]] and mixed with [[essential oils]] high in [[eugenol]] and [[thymol]] (such as thyme and clove oils). Antiperspirants may also contain [[levomethamphetamine]].{{sfn|Kasture|Gokhal|Parakh|Paradkar|2008|p=15.16}}

==Pathology==

Some diseases of the sweat glands include:

; [[Fox-Fordyce disease]] : The apocrine sweat glands become inflamed, causing a persistent, itchy rash, usually in the axillae and pubic areas.<ref name=dorland-disease>{{cite encyclopedia| publisher = Saunders| title = disease| encyclopedia = Dorland's Medical Dictionary for Health Consumers| access-date = 3 January 2013| year = 2007| url = http://medical-dictionary.thefreedictionary.com/Sandhoff%27s+disease}}</ref>
; [[Frey's syndrome|Frey's Syndrome]]: If the auriculotemporal nerve is damaged (most often as a result of a [[Parotidectomy]]), excess sweat can be produced in the rear of the cheek area (just below the ear) in response to stimuli that cause salivation.<ref name="NEJM">{{cite journal|title=Frey's Syndrome|year=2006 |journal= New England Journal of Medicine|volume=355 |issue=1 |pages=66 |doi=10.1056/NEJMicm040462|pmid=16822997 |last1 = Prattico|first1 = Francesco|last2=Perfetti |first2=Paola }}</ref>
; [[Heatstroke]]: When the eccrine glands become exhausted and unable to secrete sweat. Heatstroke can lead to fatal [[Fever#Hyperpyrexia|hyperpyrexia]] (extreme rise in body temperature).<ref name=britannica-skindis />
; [[Hidradenitis suppurativa]]: Occurs when the skin and sweat glands become inflamed with swollen lumps. These are typically painful and break open, releasing fluid or pus. The most commonly affected areas are the underarms, under the breasts, and the groin.
; [[Hyperhidrosis]]: (also known as '''polyhidrosis''' or '''sudorrhea''') is a pathological, excessive sweating that can be either generalized or localized ([[focal hyperhidrosis]]); focal hyperhidrosis occurs most often on the palms, soles, face, scalp and axillae. Hyperhidrosis is usually brought on by emotional or thermal stress,{{sfn|Tsai|2006|p=496}} but it can also occur or with little to no stimulus.<ref name=britannica-skindis /> Local (or asymmetrical) hyperhidrosis is said to be caused by problems in the [[sympathetic nervous system]]: either lesions{{sfn|Tsai|2006|p=496}} or nerve inflammation.<ref name=britannica-hyper /> Hyperhidrosis can also be caused by [[trench foot]] or [[encephalitis]].<ref name=britannica-hyper />
; [[Miliaria#Miliaria rubra|Milaria rubra]]: Also called '''prickly heat'''. Milaria rubra is the rupture of sweat glands and migration of sweat to other tissues. In hot environments, the skin's [[stratum corneum|horny layer]] can expand due to sweat retention, blocking the ducts of eccrine sweat glands. The glands, still stimulated by high temperatures, continues to secrete. Sweat builds up in the duct, causing enough pressure to rupture the duct where it meets the epidermis. Sweat also escapes the duct to adjacent tissues (a process called ''milaria'').<ref name=britannica-skindis />{{sfn|James|Berger|Elston|2011|p=19}} Hypohydrosis then follows milaria (postmiliarial hypohydrosis).{{sfn|James|Berger|Elston|2011|p=20}}
; Osmidrosis: Often called '''bromhidrosis''', especially in combination with hyperhidrosis. Osmohidrosis is excessive odor from apocrine sweat glands (which are overactive in the axillae).{{sfn|Tsai|2006|p=496}} Osmidrosis is thought to be caused by changes in the apocrine gland structure rather than changes in the bacteria that acts on sweat.{{sfn|Tsai|2006|p=497}}

===Tumors===
Sweat gland tumors include:{{sfn|James|Berger|Elston|2011}}<ref name="pmid34197659">{{cite journal | vauthors = Plotzke JM, Adams DJ, Harms PW | title = Molecular pathology of skin adnexal tumours | journal = Histopathology | volume = 80 | issue = 1 | pages = 166–183 | date = January 2022 | pmid = 34197659 | doi = 10.1111/his.14441 | hdl = 2027.42/171211 | s2cid = 235714739 | url = | hdl-access = free }}</ref>
{{div col}}
* [[Acrospiroma]]
* [[Aggressive digital papillary adenocarcinoma]]
* [[Apocrine gland carcinoma]]
* [[Ceruminoma]]
* Cutaneous [[myoepithelioma]]
* [[Cylindroma]]
* [[Eccrine carcinoma]]
* [[Hidradenoma papilliferum]]
* [[Hidrocystoma]]
* [[Microcystic adnexal carcinoma]]
* [[Mucinous carcinoma]]
* [[Papillary eccrine adenoma]]
* [[Poroma]]
* [[Porocarcinoma]]
* [[Syringadenoma papilliferum]]
* [[Syringofibroadenoma]]
* [[Syringoma]]
{{div col end}}

Adenolipomas are [[lipomas]] associated with eccrine sweat glands.{{sfn|James|Berger|Elston|2011|p=612}}

===As signs in other illnesses===
Many diseases cause sweat gland dysfunction:

*[[Acromegaly]], a result of excess [[growth hormone]], causes the size of sweat glands increase, which leads to thicker skin.{{sfn|Rubin|Strayer|2011|p=1043}}
*[[Aquagenic wrinkling of the palms]], in which white [[papules]] develop on the palms after exposure to water, can sometimes come with abnormal [[aquaporin 5]] in the sweat glands.{{sfn|James|Berger|Elston|2011|p=210}}
*[[Cystic fibrosis]] can be diagnosed by a [[sweat test]], as the disease causes the sweat glands ducts to reabsorb less chloride, leading to higher concentrations of chloride in the secreted sweat.<ref name=bernstein11>{{cite book| publisher = Lippincott Williams & Wilkins| isbn = 9780781770309| last1 = Bernstein| first1 = Daniel | first2 = Steven P.|last2= Shelov| title = Pediatrics for Medical Students| url = https://archive.org/details/pediatricsformed00dani| url-access = limited| date = 29 July 2011|page=[https://archive.org/details/pediatricsformed00dani/page/n523 504]}}</ref>
*[[Ectodermal dysplasia]] can present a lack of sweat glands.<ref name=medline-ectodermal>{{cite encyclopedia| publisher = U.S. National Library of Medicine| title = Ectodermal dysplasia| encyclopedia = MedlinePlus Medical Encyclopedia| access-date = 2 January 2013| url = https://www.nlm.nih.gov/medlineplus/ency/article/001469.htm}}</ref>
*[[Fabry disease]], characterized by excess [[globotriaosylceramide]] (GL3), causes a decrease in sweat gland function due to GL3 deposits in the eccrine glands.<ref name=elstein10>{{cite book| publisher = Springer| isbn = 9789048190331| last = Elstein| first = Deborah| title = Fabry Disease| date = 1 January 2010|pages=84, 358}}</ref>
*[[GM1 gangliosidoses|GM<sub>1</sub> gangliosidoses]], characterized by abnormal lipid storage, leads to [[vacuolization]] in eccrine sweat gland cells.<ref name=drut78>{{cite journal| doi = 10.1111/j.1600-0560.1978.tb00935.x| issn = 1600-0560| volume = 5| issue = 1| pages = 35–36| last = Drut| first = Ricardo| title = Eccrine Sweat Gland Involvement in GM1 Gangliosidosis| journal = Journal of Cutaneous Pathology|year = 1978| pmid = 418085| s2cid = 43884684}}
</ref>
*[[Hunter syndrome]] can include metachromin [[Granule (cell biology)|granules]] and [[mucin]] in the [[cytoplasm]] of the eccrine sweat gland cells.{{sfn|James|Berger|Elston|2011|p=534}}
*[[Hypothyroidism]]'s low levels of [[thyroid hormone]] lead to decreased secretions from sweat glands; the result is dry, coarse skin.{{sfn|Rubin|Strayer|2011|p=1048}}
*[[Kearns–Sayre syndrome]], a [[mitochondrial myopathy|disease of the mitochondria]], involves abnormal [[mitochondria]] in eccrine sweat glands.<ref name=martin84>{{cite book| publisher = Springer| isbn = 9789061938071| page = 367| editor-first = A. |editor-last=Neetens|editor3-first= J. J.|editor3-last= Martin |editor2-first=A. |editor2-last=Lowenthal| last = Martin| first = J. J.| title = Visual System in Myelin Disorders| chapter = Neuropathological Diagnostic Methods| location = The Netherlands| date = 31 January 1984 }}</ref>
*[[Lafora disease]] is a rare genetic disorder marked by the presence of abnormal [[polyglucosan]] deposits. These "Lafora bodies" appear in the ducts of sweat glands, as well as the myoepithelial cells of apocrine glands.<ref name=rubio92>{{cite journal| issn = 0022-3050| volume = 55| issue = 11| pages = 1084–1085| last1 = Rubio| first1 = G.| first2 = C. |last2=Garcia Guijo|first3= J. J.|last3= Mallada|first4=A. |last4=Cabello|first5= A. |last5=Garcia Merino| title = Diagnosis by axilla skin biopsy in an early case of Lafora's disease| journal = Journal of Neurology, Neurosurgery, and Psychiatry| date = November 1992|pmid=1469407|pmc=1015298 | doi=10.1136/jnnp.55.11.1084}}</ref>
*[[Lichen striatus]], a [[self-limiting (biology)|self-limited]] eruption of small, slightly scaly [[papule]]s, includes a [[lymphoid]] [[infiltration (medical)|infiltrate]] around eccrine sweat glands.{{sfn|James|Berger|Elston|2011|p=223–224}}
*[[Metachromatic leukodystrophy]], a lysosomal storage disease, leads to the accumulation of lipopigments and lysosomal residual bodies in the epithelial cells of sweat glands.<ref name=goebel-89>{{cite book| issn = 0065-2598| volume = 266| pages = 299–309| last1 = Goebel| first1 = H. H.| first2 = H.|last2= Busch| title = Lipofuscin and Ceroid Pigments| chapter = Abnormal Lipopigments and Lysosomal Residual Bodies in Metachromatic Leukodystrophy| series = Advances in Experimental Medicine and Biology| date = 1990| doi=10.1007/978-1-4899-5339-1_21| doi-broken-date = 1 November 2024| pmid = 2486156| isbn = 978-1-4899-5341-4}}</ref>
*[[Neuronal ceroid lipofuscinosis]] causes abnormal deposits of lipopigment in sweat gland epithelial cells (among other places).<ref name=carlen01>{{cite journal| issn = 0191-3123| volume = 25| issue = 4| pages = 285–288| last1 = Carlén| first1 = B.| first2 = E.|last2= Englund| title = Diagnostic value of electron microscopy in a case of juvenile neuronal ceroid lipofuscinosis| journal = Ultrastructural Pathology| date = August 2001|pmid=11577772| doi=10.1080/019131201753136296| s2cid = 22200975}}</ref>
*[[Neutral lipid storage disease]] includes abnormal lipid deposits in cells, including those of the sweat gland.{{sfn|James|Berger|Elston|2011|p=555}}
*[[Niemann–Pick disease, type C|Niemann-Pick disease type C]], another [[lipid storage disease]], includes abnormal lipid storage in sweat glands.<ref name=elleder75>{{cite journal| issn = 0001-6322| volume = 33| issue = 3| pages = 191–200| last1 = Elleder| first1 = M.| first2 = A.|last2= Jirásek|first3= F.|last3= Smíd| title = Niemann-Pick disease (Crocker's type C): A histological study of the distribution and qualitative differences for the storage process| journal = Acta Neuropathologica| date = 19 December 1975| doi=10.1007/bf00688393| pmid = 1211110| s2cid = 28257992}}</ref>
*[[Schindler disease]] causes cytoplasmic [[vacuole]]s that appear to be empty or contain filamentous material to manifest in eccrine sweat gland cells.<ref name=pavelka10>{{cite book| publisher = Springer| isbn = 9783211993903| last1 = Pavelka| first1 = Margit| first2 = Jurgen|last2= Roth| title = Functional Ultrastructure: Atlas of Tissue Biology and Pathology| url = https://archive.org/details/functionalultras00pave| url-access = limited| date = 1 January 2010|page=[https://archive.org/details/functionalultras00pave/page/n346 332]}}</ref>
*[[Small fiber peripheral neuropathy]] can damage the nerves that control the sweat glands. The sweat gland nerve fiber density test can diagnose this condition.<ref>{{cite web|title=Sweat Gland Nerve Fiber Density|url=https://www.therapath.com/Sweat_Gland_Nerve_Fiber_Density.php|publisher=Therapath|access-date=2013-08-05|archive-date=2013-12-08|archive-url=https://web.archive.org/web/20131208054535/http://therapath.com/Sweat_Gland_Nerve_Fiber_Density.php|url-status=dead}}</ref>

==See also==
* [[Sudomotor]]

==Gallery==
{|
|[[File:Gray940 - sweat gland.png|thumb|upright|Transverse view of the skin with sweat glands highlighted]]
|[[File:Gray893 - sweat glands.png|thumb|110px|Transverse view of the eyelid with sweat glands highlighted]]
|}

==Notes==
{{Reflist|30em|refs=
<ref name=Ackerman2005>{{cite book|last1=Ackerman|first1=A. Bernard|title=Histologic Diagnosis of Inflammatory Skin Diseases An Algorithmic Method Based on Pattern Analysis|year=2005|isbn=9781893357259|chapter=Embryologic, Histologic, and Anatomic Aspects|chapter-url=http://www.derm101.com/content/13501|first2=Almut|last2=Böer|first3=Bruce|last3=Bennin|first4=Geoffrey J.|last4=Gottlieb|publisher=Ardor Scribendi |url-status=dead|archive-url=https://web.archive.org/web/20110421033058/http://www.derm101.com/content/13501|archive-date=2011-04-21}}</ref>
<ref name=americanheritage>{{cite encyclopedia|encyclopedia=The American Heritage Medical Dictionary|year= 2007|publisher= Houghton Mifflin Company|postscript=,}} cited in {{cite encyclopedia|encyclopedia=The Free Dictionary|publisher=Farlex|title=apocrine sweat gland|url=http://medical-dictionary.thefreedictionary.com/apocrine+sweat+gland|access-date=6 June 2013}}</ref>
<ref name=britannica-skindis>{{cite encyclopedia| publisher = Encyclopædia Britannica, Inc.| title = skin disease| encyclopedia = Britannica Online Encyclopedia| access-date = 18 December 2012| url = http://www.britannica.com/EBchecked/topic/1800121/skin-disease/26820/Hair-and-pilosebaceous-follicles}}</ref>
<ref name=britannica-hyper>{{cite encyclopedia| publisher = Encyclopædia Britannica, Inc.| title = hyperhidrosis| encyclopedia = Britannica Online Encyclopedia| access-date = 18 December 2012| url = http://www.britannica.com/EBchecked/topic/279591/hyperhidrosis}}</ref>
<ref name=bullard70>{{cite journal | last1=Bullard |first1=R. W.|last2=Dill|first2=D. B.|last3= Yousef |first3=M. K. | title=Responses of the burro to desert heat stress | journal=Journal of Applied Physiology | year=1970 | volume=29 | pages=159–67 |issue=2 | pmid=5428889|doi=10.1152/jappl.1970.29.2.159}}</ref>
<ref name=caceci>{{cite web| last = Caceci| first = Thomas| publisher = Virginia–Maryland Regional College of Veterinary Medicine| title = Integument I: Skin| work = VM8054 Veterinary Histology Laboratory Exercises| access-date = 19 December 2012| url = http://www.vetmed.vt.edu/education/curriculum/vm8054/labs/lab14/lab14.htm| url-status = dead| archive-url = https://archive.today/20130106124235/http://www.vetmed.vt.edu/education/curriculum/vm8054/labs/lab14/lab14.htm| archive-date = 6 January 2013}}</ref>
<ref name=dorlands>{{cite encyclopedia|encyclopedia=Dorland's Medical Dictionary for Health Consumers|year=2007|publisher=Saunders|postscript=,}} cited in {{cite encyclopedia|encyclopedia=The Free Dictionary|publisher=Farlex|title=apocrine sweat gland|url=http://medical-dictionary.thefreedictionary.com/apocrine+sweat+gland|access-date=6 June 2013}}</ref>
<ref name=draelos10>{{cite book| publisher = Springer| isbn = 9781849960267| editor-first = R. A.|editor-last= Norman| last = Draelos| first = Zoe Diana| title = Preventive Dermatology| url = https://archive.org/details/preventivedermat00norm| url-access = limited| chapter = Prevention of Cosmetic Problems| year = 2010|doi=10.1007/978-1-84996-021-2_16|page=[https://archive.org/details/preventivedermat00norm/page/n183 182]}}</ref>
<ref name=grayanat>{{cite book| edition = 20th| publisher = Lea & Febiger| last = Gray| first = Henry| title = Anatomy of the Human Body| chapter = The Organs of the Senses and the Common Integument| location = Philadelphia| year = 1918|chapter-url=http://www.bartleby.com/107/234.html}}</ref>
<ref name=kennedy94>{{cite journal| issn = 0270-6474| volume = 14| issue = 11 pt. 2| pages = 6825–33| last1 = Kennedy| first1 = W. R.| first2 = G.|last2= Wendelschafer-Crabb|first3= T. C.|last3= Brelje| title = Innervation and vasculature of human sweat glands: an immunohistochemistry-laser scanning confocal fluorescence microscopy study| journal = The Journal of Neuroscience| date = November 1994| doi = 10.1523/JNEUROSCI.14-11-06825.1994| pmc = 6577260| pmid = 7525893}}</ref>
<ref name=merck>{{cite web|author1=Merck Sharp |author2=Dohme Corp. | title = Cutaneous Apocrine Gland Tumors| work = The Merck Veterinary Manual| url = http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/72208.htm}}</ref>
<ref name=mosby>{{cite encyclopedia|encyclopedia=Mosby's Medical Dictionary|edition=8th|year=2009|publisher=Elsevier|title=apocrine sweat gland|postscript=,}} cited in {{cite encyclopedia|encyclopedia=The Free Dictionary|publisher=Farlex|title=apocrine sweat gland|url=http://medical-dictionary.thefreedictionary.com/apocrine+sweat+gland|access-date=6 June 2013}}</ref>
<ref name=neas>{{cite book| edition = 4th| publisher = Benjamin Cumings| last = Neas| first = John F.| editor1-first = Frederic H.| editor1-last = Martini| editor2-first = Michael J.| editor2-last = Timmons| editor3-first = Bob| editor3-last = Tallitsch| title = Embryology Atlas| chapter = Development of the Integumentary System| chapter-url = http://cwx.prenhall.com/bookbind/pubbooks/martini10/chapter4/custom3/deluxe-content.html| archive-url = https://web.archive.org/web/20120808215604/http://cwx.prenhall.com/bookbind/pubbooks/martini10/chapter4/custom3/deluxe-content.html| archive-date = 2012-08-08}}</ref>
<ref name=randall46>{{cite journal| issn = 0021-9738| volume = 25| issue = 5| pages = 761–767| last = Randall| first = Walter C.| title = Quantitation and Regional Distribution of Sweat Glands in Man 1| journal = Journal of Clinical Investigation| date = September 1946|pmid=16695370|pmc=435616| doi=10.1172/JCI101760}}</ref>
<ref name=saunders03>{{cite encyclopedia| edition = 7th| publisher = Saunders| title = sweat gland| encyclopedia = [[Miller-Keane Encyclopedia & Dictionary of Medicine, Nursing, and Allied Health]]| access-date = 18 December 2012| year = 2003| url = http://medical-dictionary.thefreedictionary.com/sweat+gland}}</ref>
<ref name=slatter03>{{cite book| publisher = Elsevier Health Sciences| isbn = 9780721686073| volume = 2| editor-first = Douglas H.|editor-last= Slatter| title = Textbook of Small Animal Surgery| year = 2003|page=253}}</ref>
<ref name=vanlommel>{{cite book| publisher = Springer| isbn = 9781402072574| last = Van Lommel| first = Alfons T. L.| title = From Cells to Organs: A Histology Textbook and Atlas| url = https://archive.org/details/fromcellstoorgan00phda| url-access = limited| year = 2003|pages=[https://archive.org/details/fromcellstoorgan00phda/page/n209 199], 201}}</ref>
}}

==References==
<!--Notes are for ease of alphabetizing-->
*<!--Eroschenko-->{{cite book| publisher = Lippincott Williams & Wilkins| isbn = 9780781770576| pages = [https://archive.org/details/difioresatlashis00eros/page/n231 212]–234| last = Eroschenko| first = Victor P.| title = DiFiore's Atlas of Histology with Functional Correlations| url = https://archive.org/details/difioresatlashis00eros| url-access = limited| chapter = Integumentary System| year = 2008}}
*<!--Folk Jr-->{{cite journal| doi = 10.1007/BF01049065| issn = 0020-7128| volume = 35| issue = 3| pages = 180–186| last1 = Folk| first1 = G. Edgar Jr.| first2 = A. Jr.|last2=Semken| title = The evolution of sweat glands| journal = International Journal of Biometeorology| date = 1 September 1991| bibcode = 1991IJBm...35..180F| pmid = 1778649| s2cid = 28234765}}
*<!--Kasture-->{{cite book| edition = 10| publisher = Nirali Prakashan| isbn = 9788185790220| last1 = Kasture| first1 = P. V.| first2 = S. B.|last2= Gokhal|first3= S. R. |last3=Parakh|first4= A. R.|last4= Paradkar| title = Pharmaceutics-II: Second Year Diploma in Pharmacy| date = 7 September 2008|pages=15.14–15.16}}
*<!--Kurosumi-->{{cite book| publisher = Academic Press| isbn = 9780123644879| pages = 253–330| editor1-first = Geoffrey H.|editor1-last= Bourne| editor2-last = Danielli| editor2-first = James F.| first1 = Kazumasa |last1=Kurosumi|first2=Susumu |last2=Shibasaki|first3=Toshiho |last3=Ito| title = Protein Diffusion in Cell Membranes: Some Biological Implications| chapter = Cytology of the Secretion in Mammalian Sweat Glands| location = Orlando, Florida| year = 1984}}
*<!--James-->{{cite book| edition = 11th| publisher = Elsevier| isbn = 9781437703146| last1 = James| first1 = William D.| first2 = Timothy G. |last2=Berger|first3= Dirk M.|last3= Elston| title = Andrews' Diseases of the Skin: Clinical Dermatology|location=London|year=2011}}
*<!--Krstic-->{{cite book| publisher = Springer| isbn = 9783540536666| last = Krstic| first = Radivoj V.| title = Human Microscopic Anatomy: An Atlas for Students of Medicine and Biology| date = 18 March 2004|pages=464, 466–469}}
*<!--Rubin-->{{cite book| publisher = Lippincott Williams & Wilkins| isbn = 9781605479682| last1 = Rubin| first1 = Raphael | first2= David Sheldon |last2=Strayer| title = Rubin's Pathology: Clinicopathologic Foundations of Medicine| url = https://archive.org/details/rubinspathologyc00mdra| url-access = limited| date = 29 March 2011|pages=[https://archive.org/details/rubinspathologyc00mdra/page/n1058 1043], 1048}}
*<!--Shibasaki-->{{cite journal | doi=10.1152/japplphysiol.01124.2005 | issn=8750-7587 | volume=100 | issue=5 | last1=Shibasaki | first1=Manabu | last2=Wilson|first2= Thad E.|last3= Crandall|first3= Craig G. | title=Neural control and mechanisms of eccrine sweating during heat stress and exercise | journal=Journal of Applied Physiology | year=2006 | pages=1692–1701 | pmid=16614366}}
*<!--Sorensen-->{{cite journal |first1=Vibeke W.|last1=Sørensen|first2=Gaya|last2=Prasad| title=On the fine structure of horse sweat glands | journal=Zeitschrift für Anatomie und Entwicklungsgeschichte | year=1973 | volume=139 | pages=173–183 | doi= 10.1007/BF00523636 | issue=2 | pmid=4352229|s2cid=9847627}}
*<!--Slegers-->{{cite journal| doi = 10.1007/BF00362480| issn =1432-2013| volume = 279| issue = 3| pages = 265–273| last = Slegers| first = J. F. G.| title = The mechanism of sweat-secretion| journal = Pflügers Archiv für die gesamte Physiologie des Menschen und der Tiere| year = 1964| pmid =14194022| s2cid =9644549}}
*<!--Tsai-->{{cite book| publisher = Springer| isbn = 9783540280439| editor-first = Melvin A. |editor-last=Shiffman| editor2-last = Di Giuseppe| editor2-first = Alberto| first = Ren-Yu |last=Tsai| title = Liposuction: Non-Cosmetic Applications| chapter = Treatment of Excessive Axillary Sweat Syndrome (Hyperhidrosis, Osmidrosis, Bromhidrosis) with Liposuction| location = Germany| date = 1 January 2006<!--|pages=496–501-->|pages=496–497}}
*<!--Wilke-->{{cite journal| doi = 10.1111/j.1467-2494.2007.00387.x| issn = 1468-2494| volume = 29| issue = 3| pages = 169–179| last1 = Wilke| first1 = K.| first2 = A.|last2= Martin|first3= L. |last3=Terstegen|first4= S. S.|last4= Biel| title = A short history of sweat gland biology| journal = International Journal of Cosmetic Science| date = June 2007| pmid=18489347| doi-access = free}}

==External links==
*[http://www2.victoriacollege.edu/dept/bio/Belltutorials/Histology%20Tutorial/Integumentary%20Web%20Page/Integumenary%20Web%20Site.html#Accessory%20structures%20B Histology of sweat glands]

{{Integumentary system}}
{{Authority control}}

[[Category:Glands]]
[[Category:Exocrine system]]
[[Category:Skin anatomy]]