Dictionary

Labs and diagnostics

Lab values with their normal and critical ranges, and the tests nurses prepare clients for.

B-type natriuretic peptideA hormone released by the heart's lower chambers when they are stretched, measured with a blood test.

base excessA value on an arterial blood gas that shows how much more or less base (buffer) the blood holds than normal.

basic metabolic panelA group of eight blood tests that check blood glucose, electrolytes, calcium and kidney function.

basophilThe least common type of white blood cell, which releases histamine during allergic and inflammatory reactions.

bicarbonateA base in the blood that balances acid; the kidneys control it, and its level is measured on blood gas and chemistry tests.

biliAn informal short form of bilirubin, as in "bili level" or "bili lights."

bilirubinA yellow pigment made when old red blood cells break down, which the liver clears into bile.

biopsyTaking a small sample of tissue from the body so it can be looked at under a microscope.

bladder scanA quick bedside ultrasound that measures how much urine is in the bladder.

blood alcohol levelA test of how much alcohol is in the blood, given as a percentage or in mg/dL.

blood cellAny of the cells carried in the blood: red cells, white cells or platelets.

blood cultureA test in which blood is placed in bottles and watched to see whether bacteria or fungi grow from it.

blood glucoseThe amount of sugar (glucose) in the blood at the time it is measured.

blood typeThe group a person's blood belongs to, based on markers on the red blood cells: A, B, AB or O, and Rh positive or negative.

blood urea nitrogenA blood test that measures urea nitrogen, a waste product made when the body breaks down protein.

BMIBody mass index: a number worked out from a person's weight and height that sorts weight into categories.

bone density scanA low-dose x-ray test that measures how much mineral is in the bones, usually at the hip and lower spine.

bronchoscopyA procedure in which a thin, lighted tube with a camera is passed through the nose or mouth to look inside the airways.

BUN-to-creatinine ratioThe blood urea nitrogen value divided by the creatinine value, used to help find the cause of a change in kidney tests.