Platelet count

Alternative names:

thrombocyte count

What the risks are:

• excessive bleeding
• fainting or feeling lightheaded
• hematoma (blood accumulating under the skin)
• infection (a slight risk any time the skin is broken)
• multiple punctures to locate veins

Special considerations:

Platelets may be decreased slightly from normal menstruation.

Drugs that can increase platelet counts include oral contraceptives.

Drugs that can decrease platelet counts include acetaminophen - oral, aspirin, chemotherapeutic agents, chloramphenicol, colchicine, H2 blocking agents, hydralazine, indomethacin, isoniazid, quinidine, streptomycin, sulfonamide, thiazide diuretic, and tolbutamide.

Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.