Hemolysis: Meaning, Causes, Types, Symptoms, Diagnosis & Treatment 

Introduction

Did you know that your red blood cells (RBCs) usually live for about 120 days? At the end of their lifespan, they are naturally broken down and recycled by the body through a process called hemolysis¹. 

However, if RBCs are destroyed much earlier than expected, or in larger numbers than usual, it can cause problems. This may happen because of inherited blood disorders or other medical conditions, and it can sometimes lead to anaemia or serious complications². Though many complications can be prevented or managed well when the cause is found and treated early. 

In this blog, we will explain the meaning of hemolysis, its causes and types, common symptoms, how doctors diagnose it, and the treatment options that may help. 

What Is Hemolysis?

Hemolysis means the breakdown of RBCs. This can be a normal part of how the body renews blood cells. RBCs usually circulate for about 120 days before old or damaged cells are removed¹. 

Causes of Hemolysis

Problems can occur when RBCs are destroyed faster than the bone marrow can replace them. This usually happens for two broad reasons: intrinsic causes, where the issue is within the RBCs themselves, and extrinsic causes, where something outside the RBCs damages them. 

Intrinsic (intracorpuscular) Causes

The defect is within the RBC itself, such as an abnormality in the RBC membrane, enzymes, or haemoglobin. While most intrinsic causes are inherited (present from birth), some may be acquired later in life. 

• G6PD deficiency: A genetic enzyme deficiency that makes RBCs vulnerable to certain medicines, infections, or foods such as fava beans^1,4. 
• Sickle cell disease: An inherited disorder in which RBCs can become rigid and sickle-shaped under certain conditions, such as low oxygen levels, dehydration, or acidosis. These abnormal cells break down more easily than normal RBCs, leading to hemolysis². 
• Thalassaemia: A group of inherited blood disorders that reduce haemoglobin production, leading to fragile RBCs².
• Hereditary spherocytosis: A condition in which RBCs become sphere-shaped instead of their normal disc shape, making them more likely to be destroyed by the spleen¹. 
• Pyruvate kinase deficiency: A rare inherited enzyme disorder that causes RBCs to break down faster than usual⁵. 

Extrinsic (extracorpuscular) Causes

The RBCs are structurally normal, but they are destroyed by factors outside the RBC, such as immune reactions, infections, certain medications or toxins, mechanical injury, or an enlarged spleen. These causes usually develop later in life, although not all extrinsic causes are acquired. 

• Autoimmune haemolytic anaemia (AIHA): The immune system mistakenly attacks and destroys healthy RBCs⁶. 
• Infections: Certain bacterial, viral, or parasitic infections, such as malaria, can trigger hemolysis^6,7. 
• Blood transfusion reactions: Receiving incompatible blood can cause rapid destruction of transfused RBCs⁶. 
• Mechanical damage: Artificial heart valves, ventricular assist devices, or prolonged strenuous exercise (such as marathon running) can physically damage RBCs^6,8. 
• Microangiopathic haemolytic anaemia (MAHA): RBCs are damaged as they pass through narrowed or injured small blood vessels, as seen in conditions such as thrombotic thrombocytopenic purpura and haemolytic uraemic syndrome⁹. 
• Certain cancers: Blood cancers such as lymphoma or chronic lymphocytic leukaemia may increase the risk of hemolysis¹⁰. 
• Medications, toxins, and chemicals: Exposure to certain medications, heavy metals, or certain industrial chemicals can damage RBCs⁶. 
• Hypersplenism (hyperactive spleen): An enlarged spleen may become hyperactive and trap and destroy RBCs more rapidly than normal¹¹. 

Important: Although intrinsic haemolytic anaemias are usually inherited and extrinsic haemolytic anaemias are often acquired, this is not always the case. Some intrinsic causes may be acquired, so the terms intrinsic and extrinsic do not strictly mean inherited and acquired, respectively. 

Symptoms of Hemolysis

Symptoms can vary from person to person. They may depend on how quickly RBCs are being destroyed, how severe the condition is, and what is causing it. Common hemolysis symptoms and signs include^6,12: 

• Fatigue or weakness 
• Pale skin (pallor) 
• Jaundice (which causes yellowing of the skin and eyes) 
• Dark or reddish-brown urine 
• Shortness of breath 
• Rapid heartbeat (tachycardia) 
• Dizziness or light-headedness 

Note: Dark or reddish-brown urine is more commonly seen in intravascular hemolysis due to the presence of haemoglobin in the urine (haemoglobinuria). In extravascular hemolysis, urine usually does not become dark because RBCs are broken down mainly in the spleen and liver. Dark urine caused by haemoglobinuria should also be distinguished from haematuria (blood in the urine) and myoglobinuria (muscle protein in the urine). 

Types of Hemolysis 

Doctors may describe hemolysis in different ways, depending on where RBCs are destroyed and what is causing the destruction. 

Based on the site of RBC destruction

• Extravascular hemolysis: RBCs are mainly removed and broken down by immune cells (macrophages) in the spleen and liver. This is the most common type of hemolysis. 
• Intravascular hemolysis: RBCs are destroyed within the bloodstream¹. 

Based on the cause

• Inherited (intrinsic) hemolysis: Caused by genetic disorders that affect the RBCs, such as G6PD deficiency, sickle cell disease, thalassaemia, and hereditary spherocytosis^1,2.
• Acquired (extrinsic) hemolysis: Caused by external factors, including autoimmune diseases, infections, certain medicines, blood transfusion reactions, toxins, or mechanical injury⁶.

How Is Hemolysis Diagnosed?

If your doctor suspects hemolysis, they may recommend a complete blood count to check for anaemia. They may also advise other blood or urine tests, such as⁶: 

• Absolute reticulocyte count 
• Direct Coombs (antiglobulin) test  
• Serum lactate dehydrogenase (LDH) 
• Serum haptoglobin level 
• Bilirubin test 
• Peripheral blood smear 

Additional tests, such as G6PD tests, may be recommended depending on the suspected cause. 

Treatment of Hemolysis

Treatment depends on the cause, how severe the hemolysis is, and the person’s overall health. Your doctor may recommend one or more of the following options^4,6,13: 

• Addressing the underlying cause, such as an infection or autoimmune disease. 
• Stopping or changing the medicine causing hemolysis, if applicable. 
• Blood transfusions to manage severe anaemia. 
• Supplements to support RBC production. 
• Supportive care, including intravenous fluids and oxygen therapy for severe cases. 
• Avoiding known triggers, such as certain medicines, infections, or fava beans, in people with G6PD deficiency. 
• Splenectomy (surgical removal of the spleen) in selected cases of chronic hemolysis (may increase the long-term risk of severe infections).  

Possible Complications of Hemolysis

If hemolysis is severe or not treated, it may lead to complications such as^13,14: 

• Severe jaundice 
• Gallstones 
• Acute kidney injury 
• Heart complications due to severe or prolonged anaemia 
• Life-threatening haemolytic crisis in severe cases 

Prevention Tips for Hemolysis

Not every type of hemolysis can be prevented. However, the following steps may help lower the risk of severe episodes and related complications: 

• Take medicines only as prescribed by your doctor. 
• Avoid known triggers, such as certain medicines, chemicals, or foods (e.g., fava beans in people with G6PD deficiency)⁴.
• Manage infections promptly and keep vaccinations up to date. 
• Inform your doctor if you have a history of hemolysis or an inherited blood disorder. 
• Attend regular follow-up appointments and blood tests if you have a chronic haemolytic condition. 
• Seek medical attention early if you notice symptoms such as jaundice, dark urine, unusual fatigue, or shortness of breath. 
• Consider genetic counselling if you have a family history of inherited haemolytic disorders¹³.

When Should You Consult a Doctor?

Speak to a doctor if you notice any of the following symptoms, especially if they are new, persistent, or getting worse^4,6,12,13:

• Persistent fatigue, weakness, or shortness of breath 
• Yellowing of the skin or eyes (jaundice) 
• Dark or reddish-brown urine 
• Pale skin or dizziness 
• Unexplained fever or chills 
• Pain or fullness in the upper left side of the abdomen (which may indicate an enlarged spleen) 
• Symptoms after starting a new medicine or following a blood transfusion 
• A family history of inherited blood disorders with new or worsening symptoms 

Also Read: Folate Deficiency: Meaning, Causes, Symptoms, Treatment & Prevention 

Conclusion

Hemolysis is a normal process when old RBCs are removed from the body. It becomes a concern when RBCs break down too early or too quickly. This may happen because of inherited blood disorders or acquired medical conditions. Mild cases may cause few or no symptoms, but severe cases can lead to serious complications. Recognising symptoms early, finding the cause, and getting timely treatment can make a meaningful difference. If you have symptoms that may suggest hemolysis, speak to your doctor for the right diagnosis and care. 

Frequently Asked Questions (FAQs)

References

1. Thiagarajan P, Parker CJ, Prchal JT. How Do Red Blood Cells Die? Front Physiol. 2021;12:655393. doi:10.3389/fphys.2021.655393 https://pubmed.ncbi.nlm.nih.gov/33790808/

2. Zhong H, Yazdanbakhsh K. Hemolysis and immune regulation. Curr Opin Hematol. 2018;25(3):177-182. doi:10.1097/MOH.0000000000000423 https://pmc.ncbi.nlm.nih.gov/articles/PMC6309361/

3. Hemolysis. MedlinePlus. Accessed July 20, 2026. https://medlineplus.gov/ency/article/002372.htm 

4. Mak GK, Shah M. Glucose-6-Phosphate Dehydrogenase Deficiency. StatPearls. Accessed July 20, 2026. http://www.ncbi.nlm.nih.gov/books/NBK470315/ 

5. Higa S, Keapoletswe K, Cirneanu L, Hagenaars S, LI J, Zagadailov E. P1476: The Clinical Characteristics And Overall Survival Of Patients With Pyruvate Kinase Deficiency In The UK: A Real-World Study. HemaSphere. 2023;7(Suppl):e0113950. doi:10.1097/01.HS9.0000972788.01139.50  https://pmc.ncbi.nlm.nih.gov/articles/PMC10430506/

6. Hemolytic anemia: MedlinePlus. Accessed July 20, 2026. https://medlineplus.gov/ency/article/000571.htm 

7. Thomas L. Hemolysis as Influence & Interference Factor. EJIFCC. 2002;13(4):95-98. Accessed July 20, 2026. https://pmc.ncbi.nlm.nih.gov/articles/PMC6208064/ 

8. Patil HR, O’Keefe JH, Lavie CJ, Magalski A, Vogel RA, McCullough PA. Cardiovascular Damage Resulting from Chronic Excessive Endurance Exercise. Mo Med. 2012;109(4):312-321. Accessed July 20, 2026. https://pmc.ncbi.nlm.nih.gov/articles/PMC6179786/ 

9. Chaudhary P, Maharjan N, Subedi B. Microangiopathic Hemolytic Anemia as the Initial Presentation of Metastatic Signet-Ring Cell Carcinoma of the Colon: A Case Report. Cureus. 16(12):e76034. doi:10.7759/cureus.76034 https://pubmed.ncbi.nlm.nih.gov/39835047/

10. Tozluklu NN, Güvenç B. Autoimmune Hemolytic Anemia as the Presenting Feature of Chronic Lymphocytic Leukemia: Two Contrasting Cases Across Different Age Groups. Hematol Transfus Cell Ther. 2025;47:106115. doi:10.1016/j.htct.2025.106115 https://pmc.ncbi.nlm.nih.gov/articles/PMC8616265/

11. Lv Y, Lau WY, Li Y, et al. Hypersplenism: History and current status. Exp Ther Med. 2016;12(4):2377-2382. doi:10.3892/etm.2016.3683 https://pubmed.ncbi.nlm.nih.gov/27703501/

12. Palmer D, Seviar D. How to approach hemolysis: Haemolytic anaemia for the general physician. Clin Med. 2022;22(3):210-213. doi:10.7861/clinmed.2022-0142 https://pubmed.ncbi.nlm.nih.gov/35584830/

13. Turner J, Parsi M, Badireddy M. Anemia. StatPearls. Accessed July 20, 2026. http://www.ncbi.nlm.nih.gov/books/NBK499994/ 

14. Palmer D, Seviar D. How to approach hemolysis: Haemolytic anaemia for the general physician. Clin Med. 2022;22(3):210-213. doi:10.7861/clinmed.2022-0142 https://pubmed.ncbi.nlm.nih.gov/35584830/

15. High potassium level. MedlinePlus. Accessed July 20, 2026. https://medlineplus.gov/ency/article/001179.htm 

16. Asirvatham JR, Moses V, Bjornson L. Errors in Potassium Measurement: A Laboratory Perspective for the Clinician. North Am J Med Sci. 2013;5(4):255-259. doi:10.4103/1947-2714.110426  https://pmc.ncbi.nlm.nih.gov/articles/PMC3662091/

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