It’s not normal for hemoglobin to be present in your urine. It’s usually an indication that your body is breaking down red blood cells too quickly. The underlying cause may be due to many factors, including blood disorders, infections, or medication side effects.

A clinician handles test tubes containing urine in a laboratory. Share on Pinterest
Photo credit: Getty Images

Hemoglobin is an iron-containing protein in your red blood cells that carries oxygen throughout your body. About 65% of the iron in your body is found in hemoglobin.

Hemoglobin in your urine can be a sign that red blood cells are breaking down too fast. Medically, hemoglobin in your urine is called hemoglobinuria, and the rapid breakdown of red blood cells is called hemolytic anemia.

When red blood cells break down quickly, the excess hemoglobin is carried through your bloodstream until it reaches your kidneys. Your kidneys filter it out into your urine.

Many different conditions can cause hemoglobinuria and hemolytic anemia. This article takes a closer look at some of the potential causes.

Hemoglobin isn’t a normal finding in a urine sample. Its presence suggests a medical issue.

Many different conditions can cause hemoglobin to be present in your urine, such as infections, blood diseases, and side effects from surgery or medication. The underlying conditions can range from mild to serious.

A variety of factors and conditions can potentially cause hemoglobin to be present in urine. Here are some of the most common causes.

Blood conditions

Blood conditions that can cause hemoglobin to appear in your urine include:

  • Paroxysmal nocturnal hemoglobinuria (PNH): PNH is a rare and life threatening blood disease estimated to affect 15.9 people per million. It’s characterized by symptoms such as hemoglobin in your urine, fatigue, and shortness of breath.
  • Autoimmune hemolytic anemia: Autoimmune hemolytic anemia occurs when your immune system attacks red blood cells. It’s estimated to affect about 1.77 people per 100,000.
  • Cold agglutinin disease: Cold agglutinin disease is a rare subtype of autoimmune hemolytic anemia that’s characterized by the destruction of red blood cells at temperatures around 37 to 39°F (3–4°C).
  • Sickle cell anemia:The breakdown of red blood cells is one of the main features of sickle cell anemia. Sickle cell anemia is an inherited disease where red blood cells have an abnormal crescent shape.
  • Thalassemia: Thalassemia is a genetic blood disorder characterized by a lack of hemoglobin. Some subtypes of thalassemia are linked to increased red blood cell breakdown.
  • Blood cancers: Autoimmune hemolytic anemia is linked to blood cancers. For example, it’s seen in about 10% of chronic lymphocytic leukemias.
  • Transfusion reaction: The breakdown of red blood cells can be a potential side effect of blood transfusions. It can occur due to immune or nonimmune reactions.

Infections

Infections linked to the breakdown of red blood cells include:

  • Malaria: Malaria is a parasitic infection carried by mosquitoes. The parasite itself and your immune system reacting to the parasite can lead to the destruction of red blood cells.
  • Cytomegalovirus: Cytomegalovirus is a very common virus that affects about half of people by age 40, though most people don’t experience symptoms. The breakdown of red blood cells is an increasingly recognized complication in people with healthy immune systems.
  • Viral hepatitis: Although rare, the breakdown of red blood cells has been reported after viral hepatitis infections. For example, in a 2022 study, researchers reported 20 cases associated with hepatitis E infection.
  • Epstein-Barr virus: Hemolytic anemia affects about 1% to 3% of people with infectious mononucleosis.
  • Tuberculosis: Tuberculous is caused by the bacteria Mycobacterium tuberculosis. Autoimmune hemolytic anemia is a rare complication of tuberculosis.

Other conditions

  • Severe burns: Severe burns can lead to elevated hemoglobulin levels in your blood and a low red blood cell count.
  • Medication complications: Some medications can cause the breakdown of red blood cells. Drug reactions accounted for 26% of cases of hemolysis in a small group of 27 people in a 2019 study.
  • Strenuous physical activity: Strenuous physical activity is associated with increased red blood cell breakdown. Research suggests that the breakdown of red blood cells is common after long distance or ultra running. It usually resolves within 24 to 48 hours.
  • Surgical complication: Mechanical stress from mitral valve surgery or other blood vessel procedures can cause physical damage to red blood cells.
  • Other cancers: Tumors can excrete chemicals that cause a group of complications called paraneoplastic syndromes. Autoimmune hemolytic anemia is a potential complication of paraneoplastic syndromes.
  • Enzyme deficiencies: Some enzyme deficiencies can cause the breakdown of red blood cells such as pyruvate and glucose-6-phosphate dehydrogenase deficiencies.
  • Overactive spleen: The breakdown of red blood cells is a potential complication of an overactive spleen.

Doctors can measure hemoglobin in your blood with a urine test. No special preparation is needed for the test. You’ll be given a special cup to collect your urine sample.

A healthcare professional will give you specific instructions on how to perform the test. They may tell you to take a mid-urine stream sample.

Doctors can detect hemoglobin in your sample by applying a small amount of urine to test strips.

If hemoglobin is detected in your urine, your doctor may use the following tests to help diagnose the underlying cause:

  • a physical exam
  • blood tests
  • urine tests
  • imaging tests
  • genetic tests
  • bone marrow tests

The specific treatment will depend on the underlying cause. Some conditions may not require treatment.

Potential treatments include:

  • medications to slow the breakdown of blood cells
  • blood transfusions to increase your red blood cell count
  • steroids or biologics to reduce imVmune system activity
  • immunotherapy drugs
  • rehydration with fluids administered through an intravenous (IV) line
  • treatment for underlying infections
  • oxygen administered through a mask

Hemoglobin in your urine is usually a sign that your body is breaking down red blood cells quickly. It’s not normal to find hemoglobin in your urine, and its presence is a sign of an underlying medical condition.

Many different conditions can lead to hemoglobin in your urine, including some infections, blood disorders, and genetic disorders. A doctor can help you determine the underlying cause with various tests and advise you on the best treatment options.