Medical Dictionary Definitions A-Z List
Medical Dictionary Definitions A - Z - «B»:
Blood group, ABO
Blood group, ABO: The major human blood
group system. The ABO type of a person depends upon the presence or
absence of two genes, A and B. These genes determine the
configuration of the red blood cell surface.
A person can be A, B, AB, or O. If a person has two A genes, their
red blood cells ar...
Blood in semen
Blood in semen: Blood in semen (ejaculate) is also called
hematospermia. Blood in semen can be caused by many conditions affecting the
tubes that distribute semen from the testicles
(seminal vesicles) or the
prostate gland. The most common cause of blood in semen is inflammation of the seminal ...
Blood in the eye
Blood in the eye: Medically known as a subconjunctival hemorrhage. A very common cause of a painless bloody eye usually first noticed by somebody else or by the person with it when they look in the mirror. The bleeding results from a break in a small blood vessel in the sclera, the white of the eye....
Blood in the urine
Blood in the urine: Blood in the urine is termed hematuria.
Gross hematuria refers to blood that is so plentiful in the urine that the blood is visible grossly, with just the naked eye.
Gross hematuria is in contrast to microhematuria in which the blood is visible only under a microscope: there is ...
Blood Institute, National Heart, Lung, and
Institute, National Heart, Lung, and (NHLBI): One of the National Institutes of
Health in the U.S., the NHLBI's mission is to "provide
leadership for a national research program in diseases of
the heart, blood vessels, lungs, and blood and in
transfusion medicine through support of in...
Blood pH: The acidity or alkalinity of blood. The pH of any fluid is the measure of the hydrogen ion (H-) concentration. A pH of 7 is neutral. The lower the pH, the more acidic the blood. A variety of factors affect blood pH including what is ingested, vomiting, diarrhea, lung function, endocrine f...
Blood poisoning: The medical term is
"septicemia." No matter which of
two terms-blood poisoning or septicemia-you prefer, what is
same thing, namely a "general (systemic) disease that is
due to the
and the persistence of germs (pathogenic microorganisms) or
Blood pressure: The blood pressure is the pressure of the blood within the arteries. It is produced primarily by the contraction of the heart muscle. It's
measurement is recorded by two numbers. The first (systolic pressure) is measured after
the heart contracts and is highest. The second (diastolic...
Blood pressure, high
Blood pressure, high: Also known as hypertension, high blood pressure is, by definition, a repeatedly elevated blood pressure exceeding 140 over 90 mmHg -- a systolic pressure above 140 with a diastolic pressure above 90.
Chronic hypertension is a "silent" condition. Stealthy as a cat, it ...
Blood pressure, low
Blood pressure, low: Any blood pressure that is below the normal expected for an individual in a given environment. Low blood pressure is also referred to as hypotension.
Low blood pressure is a relative term because the blood pressure normally varies greatly with activity, age, medications, and u...
Blood sugar: Blood glucose. See also: High blood sugar; Low blood sugar....
Blood sugar, high
Blood sugar, high: An elevated level of the sugar glucose in the blood. Also called hyperglycemia.
High blood sugar is a finding in a number of conditions, most notably diabetes mellitus. Elevated blood glucose leads to spillage of glucose into the urine (glucosuria) so that the urine is sugary. (Th...
Blood sugar, low
Blood sugar, low: The sugar here is glucose. Low blood
glucose constitutes hypoglycemia. Hypoglycemia is only significant when it is associated
with symptoms. It has many causes including drugs, liver disease, surgical absence of the
stomach, pre-diabetes, and rare tumors that release excess insulin...
Blood transfusion: The transfer of blood or blood
components from one person (the donor) into the bloodstream of another person (the recipient). This may be done as a
lifesaving maneuver to replace blood cells or blood products lost
through bleeding. Transfusion of your own blood (autologous)
Blood urea nitrogen
Blood urea nitrogen: Abbreviated BUN. A measure primarily of the urea level in blood. Urea is cleared by the kidney. Diseases that compromise the function of the kidney frequently lead to an increased BUN....