Haptoglobin
Liver protein that binds free hemoglobin in the blood; a marker of red blood cell breakdown
Also known as
Definition
Haptoglobin is a protein made by the liver. It binds hemoglobin that enters the blood when red blood cells break down, so the liver can remove it. When red blood cells are destroyed faster than usual (hemolysis), haptoglobin is used up and its level falls. The value is usually read together with LDH, reticulocytes, hemoglobin, hematocrit and a blood smear.
| Parameter | Value |
|---|---|
| Unit | g/l (mg/dl) |
| Reference Range | Adults: about 0.41–1.65 g/l (41–165 mg/dl). In infants under six months, low values are normal. Labs differ; the reference range on your own report is what counts. Discuss deviations with your doctor. |
Agree on your personal target range with your doctor.
1 g/l equals 100 mg/dl; 41–165 mg/dl equals 410–1,650 mg/l.
↓ What a low value means
Low haptoglobin can be linked to accelerated breakdown of red blood cells, for example in hemolytic anemia or a reaction to a blood transfusion. Liver disease and larger hematomas can also lower the value, as can some medications such as birth control pills. Discuss deviations with your doctor.
↑ What a high value means
Haptoglobin rises with inflammation. Elevated values can be linked, among other things, to ulcerative colitis, acute rheumatic inflammation of joints and muscles, severe infections, blocked bile ducts, a peptic ulcer or diabetes. Androgens and corticosteroids can also raise the value. Your doctor interprets the result together with other values.
When to test
Typical reasons are symptoms that may fit hemolytic anemia, such as fatigue, pale skin, shortness of breath, yellowing of the skin or eyes or dark urine, and a suspected reaction after a blood transfusion. No special preparation is needed. Tell your practice which medications you take, and do not stop any without talking to your doctor.
Frequently asked questions
Why is haptoglobin measured together with other values? +
A single value is not enough for interpretation. MedlinePlus lists complementary tests including reticulocytes, hemoglobin, hematocrit, LDH, a blood smear and a complete blood count. Only the combination shows whether more red blood cells are being broken down.
Which medications affect the value? +
According to MedlinePlus, androgens and corticosteroids can raise haptoglobin. Medications that can lower it include birth control pills, chlorpromazine, diphenhydramine, indomethacin, isoniazid, nitrofurantoin, quinidine and streptomycin. Never stop medication on your own; talk to your doctor.
Is a low value in babies abnormal? +
No. In infants under six months, a low haptoglobin level is normal.
Haptoglobin
Sources
Last updated: October 05, 2026
This information is for orientation only and does not replace medical advice. Reference ranges can vary by laboratory, method and country.