blood group An inherited feature on the surface of the red blood cells. A series of related blood types constitutes a blood group system, such as the Rh or ABO system. The frequencies of the ABO and Rh blood types vary from population to population. In the US, the most common type is O+ (meaning…
blood culture A test that is designed to detect microorganisms, such as bacteria and fungi, in blood. A sample of blood obtained using a sterile technique is placed in a culture medium and incubated in a controlled environment. If microorganisms grow, their type can be identified, and they can be tested against different antibiotics for…
blood count, complete See CBC.
blood conservation Actions taken during medical treatment and surgery to limit the amount of donor blood needed.
blood coagulation The aggregation of blood platelets and other blood elements to form a semisolid clot. Coagulation occurs under the influence of the clotting factors fibrinogen, prothrombin, and thrombin, which are normally activated in response to injury. Working together, these substances thicken the blood and produce fibrin, a substance that closes off the wound. When…
blood clot, estrogen-associated A blood clot associated with estrogen therapy. Blood clots are occasional but serious side effects of estrogen therapy. They occur most frequently with high doses of estrogen. Cigarette smokers on estrogen therapy are at a higher risk for blood clots than nonsmokers are. Therefore, patients requiring estrogen therapy are strongly encouraged to…
blood clot A mass of coagulated blood. A blood clot can block a major blood vessel, causing stroke or other problems.
blood cell One of several different types of cells that make up the blood. The red blood cells (erythrocytes) contain hemoglobin, which carries oxygen in the blood. The white blood cells (leukocytes) are a blood-borne part of the immune system. The platelets help blood to clot. Together, these three types of cells make up about…
blood The red fluid in the body that contains white and red blood cells, platelets, proteins, and other elements. Blood is transported throughout the body by the circulatory system. Blood flows in two directions: away from the heart (arterial blood) and toward the heart (venous blood). Arterial blood has a high concentration of oxygen and…
blocker, beta See beta blocker.
Bloch-Sulzberger syndrome See incontinentia pigmenti.
blister A collection of fluid underneath the top layer of skin (epidermis). There are many causes of blisters, including burns, friction forces, and diseases of the skin. Also known as bleb and bulla.