BLEEDING, also known as HEMORRHAGING or HAEMORRHAGING, is blood escaping from the circulatory system . Bleeding can occur internally, where blood leaks from blood vessels inside the body, or externally, either through a natural opening such as the mouth , nose , ear , urethra , vagina or anus , or through a break 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 donor's blood volume). The stopping or controlling of bleeding is called hemostasis and is an important part of both first aid and surgery . The use of cyanoacrylate glue to prevent bleeding and seal battle wound was designed and first used in the Vietnam War . Today many medical treatments use a medical version of "super glue" instead of using traditional stitches used for small wounds that need to be closed at the skin level.
* 1 Classification
* 2 Types
* 3 Causes
* 3.1 Traumatic Injury * 3.2 Medical condition
* 4 Etymology * 5 Imaging * 6 See also * 7 References * 8 External links
A subconjunctival hemorrhage is a common and relatively minor
LASIK complication. The endoscopic image of linitis
plastica , a type of stomach cancer leading to a leather bottle-like
appearance with blood coming out of it.
Grade 2 mild blood loss (clinically significant);
Grade 3 gross blood loss, requires transfusion (severe);
Grade 4 debilitating blood loss, retinal or cerebral associated with fatality
* Urinary tract
* Hematuria – blood in the urine from urinary bleeding
* 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.
* Ovarian bleeding. This is a potentially catastrophic and not so rare complication among lean patients with polycystic ovary syndrome undergoing transvaginal oocyte retrieval .
* Upper gastrointestinal bleed * Lower gastrointestinal bleed * Occult gastrointestinal bleed
Bleeding arises due to either traumatic injury, underlying medical condition, or a combination.
Traumatic bleeding is caused by some type of injury. There are different types of wounds which may cause traumatic bleeding. These include:
* Abrasion - Also called a graze, this is caused by transverse
action of a foreign object against the skin, and usually does not
penetrate below the epidermis
Excoriation - In common with Abrasion, this is caused by
mechanical destruction of the skin, although it usually has an
underlying medical cause
Hematoma - Caused by damage to a blood vessel that in turn causes
blood to collect under the skin.
Laceration - Irregular wound caused by blunt impact to soft tissue
overlying hard tissue or tearing such as in childbirth. In some
instances, this can also be used to describe an incision.
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 bleeding" denotes hemorrhage as a result of an underlying
medical condition (i.e. causes of bleeding that are not directly due
* Intravascular changes - changes of the blood within vessels (e.g. ↑ blood pressure , ↓ clotting factors ) * Intramural changes - changes arising within the walls of blood vessels (e.g. aneurysms , dissections , AVMs , vasculitides ) * Extravascular changes - changes arising outside blood vessels (e.g. H pylori infection, brain abscess , brain tumor )
The underlying scientific basis for blood clotting and hemostasis is discussed in detail in the articles, Coagulation , hemostasis and related articles. The discussion here is limited to the common practical aspects of blood clot formation which manifest as bleeding.
Some medical conditions can also make patients susceptible to bleeding. These are conditions that affect the normal hemostatic (bleeding-control) functions of the body. Such conditions either are, or cause, bleeding diatheses . Hemostasis involves several components. The main components of the hemostatic system include platelets and the coagulation system.
Platelets are small blood components that form a plug in the blood vessel wall that stops bleeding. Platelets also produce a variety of substances that stimulate the production of a blood clot. One of the most common causes of increased bleeding risk is exposure to nonsteroidal anti-inflammatory drugs (NSAIDs). The prototype for these drugs is aspirin, which inhibits the production of thromboxane. NSAIDs inhibit the activation of platelets , and thereby increase the risk of bleeding. The effect of aspirin is irreversible; therefore, the inhibitory effect of aspirin is present until the platelets have been replaced (about ten days). Other NSAIDs, such as "ibuprofen" (Motrin) and related drugs, are reversible and therefore, the effect on platelets is not as long-lived.
There are several named coagulation factors that interact in a complex way to form blood clots, as discussed in the article on coagulation . Deficiencies of coagulation factors are associated with clinical bleeding. For instance, deficiency of Factor VIII causes classic Hemophilia A while deficiencies of Factor IX cause "Christmas disease"(hemophilia B ). Antibodies to Factor VIII can also inactivate the Factor VII and precipitate bleeding that is very difficult to control. This is a rare condition that is most likely to occur in older patients and in those with autoimmune diseases. von Willebrand disease is another common bleeding disorder. It is caused by a deficiency of or abnormal function of the "von Willebrand" factor, which is involved in platelet activation. Deficiencies in other factors, such as factor XIII or factor VII are occasionally seen, but may not be associated with severe bleeding and are not as commonly diagnosed.
In addition to NSAID-related bleeding, another common cause of
bleeding is that related to the medication, warfarin ("Coumadin" and
others). This medication needs to be closely monitored as the bleeding
risk can be markedly increased by interactions with other medications.
Deficiencies of platelet function may require platelet transfusion while deficiencies of clotting factors may require transfusion of either fresh frozen plasma or specific clotting factors, such as Factor VIII for patients with hemophilia.
The word "Haemorrhage" (or hæmorrhage; using the æ ligature ) comes from Latin haemorrhagia, from Ancient Greek αἱμορραγία (haimorrhagía, “a violent bleeding”), from αἱμορραγής (haimorrhagḗs, “bleeding violently”), from αἷμα (haîma, “blood”) + -ραγία (-ragía), from ῥηγνύναι (rhēgnúnai, “to break, burst”).
Dioxaborolane chemistry enables radioactive fluoride (18F ) labeling of red blood cells , which allows for positron emission tomography (PET) imaging of intracerebral hemorrha