Haptoglobin test (serum haptoglobin test) is a blood test used to measure the level of haptoglobin in your blood. It helps doctors evaluate whether red blood cells are being destroyed faster than normal, a process called hemolysis.

When red blood cells break down, they release hemoglobin into the bloodstream. Haptoglobin binds to this free hemoglobin and removes it from circulation. If there is increased red blood cell destruction, haptoglobin gets used up, so its level in blood drops.