A blood test is a laboratory analysis performed on a blood sample that is usually extracted from a vein in the arm

using a needle, or via fingerprick. Multiple tests for specific blood components (such as a glucose test or a

cholesterol test) are often grouped together into one test panel called a blood panel or blood work. Blood tests

are often used in health care to determine physiological and biochemical states, such as disease, mineral content,

pharmaceutical drug effectiveness, and organ function. Typical clinical blood panels include a basic metabolic

panel or a complete blood count. Blood tests are also used in drug tests to detect drug abuse. In some of the

United States, a blood test is required before marriage; historically, this was previously true in more states.