Bleeding, hemorrhage, haemorrhage or blood loss, is blood escaping from the circulatory system from damaged blood vessels. Bleeding can occur internally, or externally either through a natural opening such as the mouth, nose, ear, urethra, vagina or anus, or through a puncture in the skin. Hypovolemia is a massive decrease in blood volume, and death by excessive loss of blood is referred to as exsanguination. Typically, a healthy person can endure a loss of 10–15% of the total blood volume without serious medical difficulties (by comparison, blood donation typically takes 8–10% of the donors blood volume). The stopping or controlling of bleeding is called hemostasis and is an important part of both first aid and surgery. Types
Upper head
Intracranial hemorrhage – bleeding in the skull. Cerebral hemorrhage – a type of intracranial hemorrhage, bleeding within the brain tissue itself. Intracerebral hemorrhage – bleeding in the brain caused by the rupture of a blood vessel within the head. See also hemorrhagic stroke. Subarachnoid hemorrhage (SAH) implies the presence of blood within the subarachnoid space from some pathologic process. The common medical use of the term SAH refers to the nontraumatic types of hemorrhages, usually from rupture of a berry aneurysm or arteriovenous malformation (AVM). The scope of this article is limited to these nontraumatic hemorrhages. Eyes
Subconjunctival hemorrhage – bloody eye arising from a broken blood vessel in the sclera (whites of the eyes).
Puncture Wound – Caused by an object that penetrated the skin and underlying layers, such as a nail, needle or knife. Contusion – Also known as a bruise, this is a blunt trauma damaging tissue under the surface of the skin. Crushing Injuries – Caused by a great or extreme amount of force applied over a period of time. The extent of a crushing injury may not immediately present itself. Ballistic Trauma – Caused by a projectile weapon such as a firearm. This may include two external wounds (entry and exit) and a contiguous wound between the two.The pattern of injury, evaluation and treatment will vary with the mechanism of the injury. Blunt trauma causes injury via a shock effect; delivering energy over an area. Wounds are often not straight and unbroken skin may hide significant injury. Penetrating trauma follows the course of the injurious device. As the energy is applied in a more focused fashion, it requires less energy to cause significant injury. Any body organ, including bone and brain, can be injured and bleed. Bleeding may not be readily apparent; internal organs such as the liver, kidney and spleen may bleed into the abdominal cavity. The only apparent signs may come with blood loss. Bleeding from a bodily orifice, such as the rectum, nose, or ears may signal internal bleeding, but cannot be relied upon. Bleeding from a medical procedure also falls into this category. Medical condition
"Medical bleeding" denotes hemorrhage as a result of an underlying medical condition (i.e.