Editing Internal bleeding (section)

=== Vital signs ===
Blood loss can be estimated based on heart rate, blood pressure, respiratory rate, and mental status.<ref>{{Cite book|title=Current Diagnosis & Treatment: Emergency Medicine|publisher=McGraw-Hill|isbn=978-0071701075|date=2011-05-23}}</ref> Blood is circulated throughout the body and all major organ systems through a closed loop system. When there is damage to the blood vessel or the blood is thinner than the physiologic consistency, blood can exit the vessel which disrupts this close-looped system. The [[Autonomic nervous system|autonomic nervous system (ANS)]] responds in two large ways as an attempt to compensate for the opening in the system. These two actions are easily monitored by checking the heart rate and blood pressure. Blood pressure will initially decrease due to the loss of blood. This is where the ANS comes in and attempts to compensate by contracting the muscles that surround these vessels. As a result, a person who is bleeding internally may initially have a normal blood pressure. When the blood pressure falls below the normal range, this is called [[hypotension]]. The heart will start to pump faster causing the heart rate to increase, as an attempt to get blood delivered to vital organ systems faster. When the heart beats faster than the healthy and normal range, this is called [[tachycardia]]. If the bleeding is not controlled or stopped, a patient will experience tachycardia and hypotension, which altogether is a state of shock, called [[hemorrhagic shock]].

[[Advanced trauma life support]] (ATLS) by the American College of Surgeons separates hemorrhagic shock into four categories.<ref name="Uptodate">{{cite web |last1=Colwell |first1=Christopher |title=Initial management of moderate to severe hemorrhage in the adult trauma patient |url=https://www.uptodate.com/contents/initial-management-of-moderate-to-severe-hemorrhage-in-the-adult-trauma-patient?search=hemorrhagic%20shock&source=search_result&selectedTitle=3~150&usage_type=default&display_rank=3#H2303255334 |access-date=5 March 2019 |website=UpToDate}}</ref><ref name=":3" /><ref name=":4">{{cite book|title=ATLS- Advanced Trauma Life Support - Student Course Manual|date=2018|publisher=American College of Surgeons|isbn=978-78-0-9968267|edition=10th|pages=43–52}}</ref>
{| class="wikitable mw-collapsible"
|+Classification of Hemorrhagic Shock<ref name="Uptodate" /><ref name=":3" /><ref name=":4" />
!
!Estimated blood loss
!Heart rate (per minute)
!Blood pressure
!Pulse pressure (mmHg)
!Respiratory rate (per minute)
!Other
|-
|'''Class I hemorrhage'''
|<u><</u> 15%
|Normal or minimally elevated
|Normal
|Normal
|Normal
|
* Slightly anxious
|-
|'''Class II hemorrhage'''
|15 - 30%
|100 - 120
|Normal or minimally decreased [[systolic blood pressure]]
|Narrowed
|20 - 30
|
* Mildly anxious
*Cool, clammy skin with delayed [[capillary refill]]
|-
|'''Class III hemorrhage'''
|30 - 40%
|120 - 140
|[[Systolic blood pressure]] < 90 mmHg or change in blood pressure > 20-30% from presentation
|Narrowed
|30 - 40
|
* Altered mental status (anxious, confused)
* Decreased urine output
|-
|'''Class IV hemorrhage'''
|> 40%
|<u>></u> 140
|[[Systolic blood pressure]] < 90 mmHg
|Narrowed (<u><</u> 25 mmHg)
|>35
|
* Significantly altered mental status (confused, lethargic)
* Cool, clammy skin with delayed capillary refill
* Significantly decreased or absent urine output
|}
Assessing circulation occurs after assessing the patient's airway and breathing ([[ABC (medicine)]]).<ref name=":2" /> If internal bleeding is suspected, a patient's [[circulatory system]] is assessed through [[palpation]] of [[pulse]]s and [[doppler ultrasonography]].<ref name=":1" />