Biochemical blood tests

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.

Blood tests are used to determine physiological and biochemical states, such as disease, mineral content, drug effectiveness, and organ function. They are also used in drug tests. Although the term blood test is used, most routine tests (except for most haematology) are done on plasma or serum, instead of blood cells.