This test measures the amount of a protein called C4 in your blood. You may need this test if your doctor suspects that you have an autoimmune disease.

This test measures the amount of C3 proteins in your blood. C3 proteins are part of your immune system. This test can help diagnose lupus.

A sweat chloride test is used to diagnose cystic fibrosis, a disease that causes mucus to build up in the lungs and other organs.

This test looks for abnormal proteins in your blood plasma. These abnormal proteins may mean you have a life-threatening disease called cryofibrinogenemia.

This test measures the level of a substance called creatinine in your urine. Too much creatinine may be a sign of kidney disease.

This blood test measures how well your kidneys work.

This test measures how well your kidneys are working and how well blood is flowing to them.

This test measures the amount of creatine kinase (CK), an enzyme, in your blood. The test can help your doctor find out whether you're having a heart attack.

This test measures the amount of the enzyme creatine kinase in your blood. A certain form of this enzyme can help find out whether you're having a heart attack.

This test may help in the diagnosis of two fairly uncommon medical conditions: Cushing syndrome and Addison disease. The test also screens for other diseases that affect your pituitary and adrenal glands.