Some tests require overnight fasting, taking or refraining from drugs, or changing eating habits for short periods of time. Most tests do not require special preparation. As with any blood test, the health care provider may limit certain foods or medications shortly before the test to assure an accurate sample. Afterward, there may be some throbbing . It is also used for regulation of body temperature, regulation of fluids, and acid-base equilibrium.
Plasma contains various substances dissolved in the fluid.
The cellular portion consists primarily of red blood cells, but also includes white blood cells and platelets . Because blood is used for multiple functions within the body, tests on the blood or its components may give valuable clues in the diagnosis of a multitude of medical conditions. The cost varies with the specific test. Obtaining a blood sample from some people may be more difficult than from others. The information provided herein should not be used for diagnosis or treatment of any medical condition.