Severe internal bleeding into the chest, abdomen, pelvis, or thighs can cause hemorrhagic shock or death if proper medical treatment is not received quickly.

Advanced trauma life support (ATLS) by the American College of Surgeons separates hemorrhagic shock into four categories.

[5] If internal bleeding is suspected, a patient's circulatory system is assessed through palpation of pulses and doppler ultrasonography.

[2][12] If the patient has stable vital signs, they may undergo diagnostic imaging such as a CT scan.

[4] If the patient has unstable vital signs, they may not undergo diagnostic imaging and instead may receive immediate medical or surgical treatment.

[12] The massive transfusion protocol replaces red blood cells, plasma, and platelets in varying ratios based on the cause of the bleeding (traumatic vs.

[4] It is crucial to stop the internal bleeding immediately (achieve hemostasis) after identifying its cause.

[12] Internal bleeding in the thorax and abdominal cavity (including both the intraperitoneal and retroperitoneal space) cannot be controlled with direct pressure (compression).

[4] Internal bleeding from a bone fracture in the arms or legs may be partially controlled with direct pressure using a tourniquet.

[12] After tourniquet placement, the patient may need immediate surgery to find the bleeding blood vessel.

[4] Internal bleeding where the torso meets the extremities ("junctional sites" such as the axilla or groin) cannot be controlled with a tourniquet; however there is an FDA approved device known as an Abdominal Aortic and Junctional Tourniquet (AAJT) designed for proximal aortic control, although very few studies examining its use have been published.