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 wound 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. 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 wounds 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.
A thrombus, colloquially called a blood clot, is the final product of the blood coagulation step in hemostasis. There are two components to a thrombus: aggregated platelets and red blood cells that form a plug, and a mesh of cross-linked fibrin protein. The substance making up a thrombus is sometimes called cruor. A thrombus is a healthy response to injury intended to stop and prevent further bleeding, but can be harmful in thrombosis, when a clot obstructs blood flow through healthy blood vessels in the circulatory system.
Coagulation, also known as clotting, is the process by which blood changes from a liquid to a gel, forming a blood clot. It potentially results in hemostasis, the cessation of blood loss from a damaged vessel, followed by repair. The mechanism of coagulation involves activation, adhesion and aggregation of platelets, as well as deposition and maturation of fibrin.
Fibrinolysis is a process that prevents blood clots from growing and becoming problematic. Primary fibrinolysis is a normal body process, while secondary fibrinolysis is the breakdown of clots due to a medicine, a medical disorder, or some other cause.
Cauterization is a medical practice or technique of burning a part of a body to remove or close off a part of it. It destroys some tissue in an attempt to mitigate bleeding and damage, remove an undesired growth, or minimize other potential medical harm, such as infections when antibiotics are unavailable.
Interventional radiology (IR) is a medical specialty that performs various minimally-invasive procedures using medical imaging guidance, such as x-ray fluoroscopy, computed tomography, magnetic resonance imaging, or ultrasound. IR performs both diagnostic and therapeutic procedures through very small incisions or body orifices. Diagnostic IR procedures are those intended to help make a diagnosis or guide further medical treatment, and include image-guided biopsy of a tumor or injection of an imaging contrast agent into a hollow structure, such as a blood vessel or a duct. By contrast, therapeutic IR procedures provide direct treatment—they include catheter-based medicine delivery, medical device placement, and angioplasty of narrowed structures.
In biology, hemostasis or haemostasis is a process to prevent and stop bleeding, meaning to keep blood within a damaged blood vessel. It is the first stage of wound healing. This involves coagulation, which changes blood from a liquid to a gel. Intact blood vessels are central to moderating blood's tendency to form clots. The endothelial cells of intact vessels prevent blood clotting with a heparin-like molecule and thrombomodulin, and prevent platelet aggregation with nitric oxide and prostacyclin. When endothelium of a blood vessel is damaged, the endothelial cells stop secretion of coagulation and aggregation inhibitors and instead secrete von Willebrand factor, which initiate the maintenance of hemostasis after injury. Hemostasis involves three major steps:
Internal bleeding is a loss of blood from a blood vessel that collects inside the body. Internal bleeding is usually not visible from the outside. It is a serious medical emergency but the extent of severity depends on bleeding rate and location of the bleeding. Severe internal bleeding into the chest, abdomen, retroperitoneal space, pelvis, and thighs can cause hemorrhagic shock or death if proper medical treatment is not received quickly. Internal bleeding is a medical emergency and should be treated immediately by medical professionals.
A bruise, also known as a contusion, is a type of hematoma of tissue, the most common cause being capillaries damaged by trauma, causing localized bleeding that extravasates into the surrounding interstitial tissues. Most bruises are not very deep under the skin so that the bleeding causes a visible discoloration. The bruise then remains visible until the blood is either absorbed by tissues or cleared by immune system action. Bruises which do not blanch under pressure can involve capillaries at the level of skin, subcutaneous tissue, muscle, or bone. Bruises are not to be confused with other similar-looking lesions. (Such lesions include petechia, purpura, and ecchymosis.
Generalized hypoxia is a condition in which the tissues of the body are deprived of the necessary levels of oxygen. This is not to be confused with hypoxemia, which refers to low levels of oxygen in the blood, although the two conditions often occur simultaneously, since a decrease in blood oxygen typically corresponds to a decrease in oxygen in the surrounding tissue. However, hypoxia may be present without hypoxemia, and vice versa, as in the case of infarction.
Embolization refers to the passage and lodging of an embolus within the bloodstream. It may be of natural origin (pathological), in which sense it is also called embolism, for example a pulmonary embolism; or it may be artificially induced (therapeutic), as a hemostatic treatment for bleeding or as a treatment for some types of cancer by deliberately blocking blood vessels to starve the tumor cells.
An antihemorrhagic (antihæmorrhagic) agent is a substance that promotes hemostasis. It may also be known as a hemostatic agent.
Tamponade is the closure or blockage by or as if by a tampon, especially to stop bleeding. Tamponade is a useful method of stopping a hemorrhage. This can be achieved by applying an absorbent dressing directly into a wound, thereby absorbing excess blood and creating a blockage, or by applying direct pressure with a hand or a tourniquet.
Intraparenchymal hemorrhage (IPH) is one form of intracerebral bleeding in which there is bleeding within brain parenchyma. The other form is intraventricular hemorrhage (IVH).
Bone wax is a waxy substance used to help mechanically control bleeding from bone surfaces during surgical procedures.
A caustic pencil is a device for applying topical medication containing silver nitrate and potassium nitrate, used to chemically cauterize skin, providing hemostasis or permanently destroying unwanted tissue such as a wart, skin tag, aphthous ulcers, or over-production of granulation tissue. They are not used as a treatment for minor skin cuts, and are not to be confused with a styptic pencil.
Emergency bleeding control describes actions that control bleeding from a patient who has suffered a traumatic injury or who has a medical condition that has caused bleeding. Many bleeding control techniques are taught as part of first aid throughout the world, though some more advanced techniques such as tourniquets, are often taught as being reserved for use by health professionals, or as an absolute last resort, to mitigate associated risks, such as potential loss of limbs. To manage bleeding effectively, it is important to be able to readily identify types of wounds and types of bleeding.
Portal hypertensive gastropathy refers to changes in the mucosa of the stomach in patients with portal hypertension; by far the most common cause of this is cirrhosis of the liver. These changes in the mucosa include friability of the mucosa and the presence of ectatic blood vessels at the surface. Patients with portal hypertensive gastropathy may experience bleeding from the stomach, which may uncommonly manifest itself in vomiting blood or melena; however, portal hypertension may cause several other more common sources of upper gastrointestinal bleeding, such as esophageal varices and gastric varices. On endoscopic evaluation of the stomach, this condition shows a characteristic mosaic or "snake-skin" appearance to the mucosa of the stomach.
A barrier membrane is a device used in oral surgery and periodontal surgery to prevent epithelium, which regenerates relatively quickly, from growing into an area in which another, more slowly growing tissue type, such as bone, is desired. Such a method of preventing epithelial migration into a specific area is known as guided tissue regeneration (GTR).
The Mynx Vascular Closure Device is an extravascular vascular closure device (VCD) whose deployment system is designed to minimize the discomfort commonly associated with closing the small hole in the artery following catheterization procedure. The device is manufactured by AccessClosure, Inc., a medical device company located in Mountain View, California.
