Editing Urination (section)

===Disorders===
{{category see also|Urological conditions}}
[[File:Konstantinderafrikaner.jpg|thumb|upright|Painting showing the physician [[Constantine the African]] accepting urine samples for diagnosis]]

====Clinical conditions====
Many clinical conditions or [[Urologic disease|urologic diseases]] can cause disturbances to normal urination, including:

* [[Urinary incontinence]], the inability to hold urine
** [[Stress incontinence]], incontinence as a result of external mechanical disturbances
** [[Urge incontinence]], incontinence that occurs as a result of the uncontrollable urge to urinate
** Mixed incontinence, a combination of the two types of incontinence
* [[Urinary retention]], the inability to initiate urination
* [[Overactive bladder]], a strong urge to urinate, usually accompanied by detrusor overactivity
* [[Interstitial cystitis]], a condition characterized by urinary frequency, urgency, and pain
* [[Prostatitis]], an inflammation of the prostate gland that can cause urinary frequency, urgency, and pain
* [[Benign prostatic hyperplasia]], an enlargement of the prostate that can cause urinary frequency, urgency, retention, and the dribbling of urine
* [[Urinary tract infection]], which can cause urinary frequency and [[dysuria]]
* [[Polyuria]], abnormally large production of urine, associated with, in particular, [[diabetes mellitus]] (types [[Diabetes mellitus type 1|1]] and [[Diabetes mellitus type 2|2]]), and [[diabetes insipidus]]
* [[Oliguria]], low urine output, usually due to a problem with the upper urinary tract
* [[Anuria]] refers to absent or almost absent urine output.
* [[Micturition syncope]], a vasovagal response which may cause fainting.
* [[Paruresis]], the inability to urinate in the presence of others, such as in a public toilet.
* [[Bladder sphincter dyssynergia]], a discoordination between the bladder and external urethral sphincter as a result of brain or [[spinal cord injury]]
A drug that increases urination is called a [[diuretic]], whereas [[antidiuretic]]s decrease the production of urine by the kidneys.

====Experimentally induced disorders====
{{unreferenced section|date=February 2013}}
There are three major types of bladder dysfunction due to neural lesions: (1) the type due to interruption of the afferent nerves from the bladder; (2) the type due to interruption of both afferent and efferent nerves; and (3) the type due to interruption of facilitatory and inhibitory pathways descending from the brain. In all three types the bladder contracts, but the contractions are generally not sufficient to empty the viscus completely, and residual urine is left in the bladder. [[Paruresis]], also known as shy bladder syndrome, is an example of a bladder interruption from the brain that often causes total interruption until the person has left a public area. These people (males) may have difficulty urinating in the presence of others and will consequently avoid using urinals without dividers or those directly adjacent to another person. Alternatively, they may opt for the privacy of a stall or simply avoid public toilets altogether.

=====Deafferentation=====
When the sacral dorsal roots are cut in experimental animals or interrupted by diseases of the dorsal roots such as [[tabes dorsalis]] in humans, all reflex contractions of the bladder are abolished. The bladder becomes distended, thin-walled, and hypotonic, but there are some contractions because of the intrinsic response of the smooth muscle to stretch.

=====Denervation=====
When the afferent and efferent nerves are both destroyed, as they may be by tumors of the [[cauda equina]] or [[filum terminale]], the bladder is flaccid and distended for a while. Gradually, however, the muscle of the "decentralized bladder" becomes active, with many contraction waves that expel dribbles of urine out of the urethra. The bladder becomes shrunken and the bladder wall hypertrophied. The reason for the difference between the small, hypertrophic bladder seen in this condition and the distended, hypotonic bladder seen when only the afferent nerves are interrupted is not known. The hyperactive state in the former condition suggests the development of denervation hypersensitization even though the neurons interrupted are [[preganglionic]] rather than [[postganglionic]].

=====Spinal cord injury=====
During [[spinal shock]], the bladder is flaccid and unresponsive. It becomes overfilled, and urine dribbles through the sphincters ([[overflow incontinence]]). After spinal shock has passed, a spinally mediated voiding reflex ensues, although there is no voluntary control and no inhibition or facilitation from higher centers. Some paraplegic patients train themselves to initiate voiding by pinching or stroking their thighs, provoking a mild mass reflex. In some instances, the voiding reflex becomes hyperactive. Bladder capacity is reduced and the wall becomes hypertrophied. This type of bladder is sometimes called the spastic neurogenic bladder. The reflex hyperactivity is made worse, and may be caused, by infection in the bladder wall.