Hemolytic anemia is a condition where the rate of destruction of red blood cells in the body exceeds the rate of their replacement. This results in a low red blood cell count, which can lead to symptoms such as weakness, shortness of breath, dizziness, and irregular heart rhythms.

A person may acquire or inherit hemolytic anemia. Causes of the acquired form may involve autoimmune disorders, infections, and bone marrow failure. In contrast, causes of the hereditary form include disorders such as thalassemia and sickle cell disease.

Treatment for this condition depends on the cause, but people may require a blood transfusion, spleen removal, certain medications, and bone marrow transplants.

Keep reading to learn more about hemolytic anemia, including its causes, symptoms, diagnosis, treatment, and outlook for someone with this condition.

Share on Pinterest
Skilled focused young phlebotomy technician applying a tourniquet to a female patient arm for venipuncture 1315395944 Svitlana Hulko/Getty Images

Red blood cells (RBCs) develop in the bone marrow, and their typical lifespan is around 120 days.

The destruction of old or nonfunctioning RBCs occurs in the spleen and other parts of the body. Hemolysis refers to the breakdown process of these red blood cells.

Too much hemolysis results in low numbers of RBCs that doctors call hemolytic anemia. It happens when RBC destruction occurs faster than their replacement. The onset may be rapid or slow, and the severity can range from mild to severe.

While hemolytic anemia can occur in anyone, the incidence is most predominant in regions of West Africa, where malaria is common.

There are many causes of hemolytic anemia that can span several categories. For example, hemolytic anemia can either be due to acquired or inherited causes.

Acquired hemolytic anemia refers to the development of the condition in people who previously had typically functioning RBC systems. On the other hand, individuals may be born with this condition, meaning they inherited it.

Acquired

Data on the prevalence and incidence of hemolytic anemia is lacking. However, a 2020 study notes that acquired hemolytic anemia is rare, and the most common acquired cause is an autoimmune condition. These are disorders where the body’s natural defenses destroy its own healthy cells.

Other causes of acquired hemolytic anemia include:

  • bone marrow failure
  • infections, such as certain bacterial or viral infections
  • complications from a blood transfusion, for example, receiving blood that does not match a person’s blood type
  • certain medications, such as dapsone — an antimalarial drug

Inherited

Inherited hemolytic anemias are a group of rare conditions that fall into several categories. The most common cause is thalassemia, a condition where the body does not produce enough hemoglobin, resulting in fewer RBCs in the body.

Another inherited cause is sickle cell disease, where the red blood cells take on the shape of a sickle rather than its typical disk shape. Sickle blood cells die early, resulting in a shortage of RBCs.

Other inherited conditions can cause:

  • Defective red blood cell membrane proteins: They can affect the structure, shape, or function of RBCs.
  • Deficiencies in red blood cell enzymes: A common type that can cause hemolytic anemia is a deficiency in the glucose-6-phosphate dehydrogenase enzyme. This enzyme protects RBCs from damage.
  • Defective production of red blood cells: For example, it can lead to congenital dyserythropoietic anemia type 2, a condition where the body does not produce red blood cells as expected.

Learn more about sickle cell disease here.

RBCs contain an iron-rich protein called hemoglobin, which enables them to carry oxygen from the lungs to all parts of the body. In hemolytic anemia, the shortage of red blood cells results in an inadequate supply of oxygen to tissues.

This leads to symptoms that include:

Symptoms may also involve blood in the urine, as well as jaundice, a yellowish appearance on the skin and whites of the eyes.

If the symptoms persist for longer periods of time, they may have:

Diagnosing hemolytic anemia involves taking a person’s medical history and performing physical exams, during which a doctor notes down their symptoms. Other tests may include:

  • blood tests to check that substances in the blood are within expected ranges and to check the total RBC volume
  • urine tests to check for blood in the urine
  • genetic tests to check if a person’s genes are affecting their ability to produce RBCs
  • bone marrow tests to check that the bone marrow is healthy and producing RBCs typically

Doctors may order a Coombs test, which checks for antibodies that specifically target RBCs and cause hemolysis. This test is helpful to diagnose if a person has autoimmune hemolytic anemia.

Learn more about autoimmune hemolytic anemia here.

Blood tests

Blood tests are necessary for determining if someone has hemolytic anemia. These tests might show:

  • increased reticulocytes, which are immature red blood cells
  • increased unconjugated bilirubin, a substance the body produces with the destruction of red blood cells
  • increased lactate dehydrogenase, a substance that forms when red blood cells rupture
  • decreased haptoglobin, a protein that binds with hemoglobin

People with mild cases of hemolytic anemia may not need treatment.

Medical interventions for other cases can depend on the cause. For instance, if a medication is causing hemolytic anemia, the treatment approach will focus on finding alternative medications.

Some treatment options for hemolytic anemia include:

Doctors may also prescribe certain medications, such as:

  • anticoagulants, for example, warfarin (Coumadin), which are drugs that help prevent blood clots
  • monoclonal antibodies, such as rituximab (Rituxan), mimic the immune system’s attack on certain targets
  • steroid medications, such as prednisone (Rayos), which can reduce inflammation
  • immunosuppressants, such as cyclosporine (Gengraf), which reduce the activity of the immune system

The outlook for someone with hemolytic anemia varies with the following:

  • the cause of the condition
  • how early a person receives a diagnosis
  • how well someone can manage their condition

For example, if the cause is an autoimmune condition and the anemia is significant at the onset, the outlook often involves a greater risk of multiple relapses. Additionally, such cases frequently do not achieve effective relief with multiple treatments.

Complications

Without treatment or management, hemolytic anemia may result in:

Anemia can also be life threatening when it occurs alongside other disorders, such as:

Hemolytic anemia in children may stem from a hereditary condition, but they may also acquire it. The symptoms, diagnosis, and treatment are the same as those that relate to adults.

Some cases may be mild in children. It is worth noting that many children with hemolytic anemia do not manifest symptoms or receive a diagnosis until they reach adulthood and develop complications.

Hemolytic anemia occurs when the breakdown of RBCs occurs faster than the body can replace them. It results in a low count of RBCs that supply oxygen to the body.

The resulting low oxygen in the tissues leads to symptoms such as weakness and dizziness. Additionally, the condition can cause blood in the urine, jaundice, and swollen lymph nodes.

Blood transfusions are the mainstay of treatment in severe cases. Other treatments vary depending on the cause of hemolytic anemia, but they may also involve surgically removing the spleen, bone marrow transplants, and various medications.

The outlook also varies with the condition’s cause, along with the onset and effectiveness of treatment.