Hemolytic anemia
Anemia - hemolytic
Anemia is a condition in which the body does not have enough healthy red blood cells. Red blood cells provide oxygen to body tissues.
Normally, red blood cells last for about 120 days in the body. In hemolytic anemia, red blood cells in the blood are destroyed earlier than normal.
Sickle cell anemia is an inherited blood disease in which the red blood cells produce abnormal pigment (hemoglobin). The abnormal hemoglobin causes deformity of the red blood cells into crescent or sickle-shapes, as seen in this photomicrograph.
Sickle cell anemia is an inherited disorder in which abnormal hemoglobin (the red pigment inside red blood cells) is produced. The abnormal hemoglobin causes red blood cells to assume a sickle shape, like the ones seen in this photomicrograph.
These crescent or sickle-shaped red blood cells (RBCs) are present with Sickle cell anemia, and stand out clearly against the normal round RBCs. These abnormally shaped cells may become entangled and block blood flow in the small blood vessels (capillaries).
This photomicrograph of red blood cells (RBCs) shows both sickle-shaped and Pappenheimer bodies.
Blood is comprised of red blood cells, platelets, and various white blood cells.
Causes
The bone marrow is mostly responsible for making new red cells. Bone marrow is the soft tissue in the center of bones that helps form all blood cells.
Hemolytic anemia occurs when the bone marrow isn't making enough red cells to replace the ones that are being destroyed.
There are several possible causes of hemolytic anemia. Red blood cells may be destroyed due to:
- An autoimmune problem in which the immune system mistakenly sees your own red blood cells as foreign substances and destroys them
- Genetic defects within the red cells (such as sickle cell anemia, thalassemia, and G6PD deficiency)
- Exposure to certain chemicals, medicines, and toxins
- Infections
- Blood clots in small blood vessels
- Transfusion of blood from a donor with a blood type that does not match yours
Do you feel tired and listless? Do you find your mind drifting during the day? Do you get dizzy or short of breath whenever you climb the stairs? There are a few possible reasons for the way you feel, but you could have anemia. You could even have anemia without noticing any symptoms at all. Anemia is a problem with hemoglobin, a substance in red blood cells that carries oxygen throughout your body. Without enough hemoglobin, your heart and other organs can't get the oxygen they need to work. When your organs slow down, you slow down and you start feeling tired and listless. Many different health conditions can cause anemia, from heavy blood loss during a woman's period, to pregnancy, to an underactive thyroid gland. Healthy red blood cells are made in your bone marrow, the soft tissue in the middle of your bones. Any disease that damages blood marrow, such as lymphoma or leukemia, can also affect your red blood cell production. Anemia can also be caused by an immune system problem that damages red blood cells, or surgery to the stomach or intestines. How do you know if you have anemia? You may feel tired, dizzy, and have trouble concentrating. You may get sick more often. People with anemia often complain of chest pain, headaches, or shortness of breath. Your skin might look pale, like you haven't seen the sun for months. Because these can also be symptoms of other conditions, your doctor will confirm that you have anemia by taking a blood test to check your red blood cell count and hemoglobin level. Blood tests can also look for problems that may be causing your anemia, such as a vitamin or iron deficiency. If you are anemic, it's very important to treat it. When your body isn't getting enough oxygen, it can starve vital organs like your heart. This can lead to a heart attack. How you treat anemia really depends on the cause. If the problem is with your bone marrow, you may take a medicine called erythropoietin, which will help your bone marrow make more red blood cells. If the problem is a vitamin or mineral deficiency, your doctor may prescribe iron, vitamin B12, or folic acid supplements. Or, you may need a blood transfusion to replace damaged red blood cells with healthy ones. How well you do really depends on what's causing your anemia. Call your doctor if you have any symptoms like fatigue or shortness of breath. Once your doctor can find and treat the cause of your anemia, you should have more energy and start feeling like your old self again.
Symptoms
You may not have symptoms if the anemia is mild. If the problem develops slowly, the first symptoms may be:
- Feeling weak or tired more often than usual, or with exercise
- Feelings that your heart is pounding or racing
- Headaches
- Problems concentrating or thinking
If the anemia gets worse, symptoms may include:
- Lightheadedness when you stand up
- Pale skin
- Shortness of breath
- Sore tongue
- Enlarged spleen
Exams and Tests
A test called a complete blood count (CBC) can help diagnose anemia and offer some hints to the type and cause of the problem. Important parts of the CBC include red blood cell count (RBC), hemoglobin, and hematocrit (HCT).
These tests can identify the type of hemolytic anemia:
- Absolute reticulocyte count
- Coombs test, direct and indirect
- Donath-Landsteiner test
- Cold agglutinins
- Free hemoglobin in the serum or urine
- Platelet count
- Protein electrophoresis - serum
- Serum immunofixation
- Pyruvate kinase
- Serum haptoglobin levels
- Serum LDH
- Carboxyhemoglobin level
Treatment
Treatment depends on the type and cause of the hemolytic anemia:
- In emergencies, a blood transfusion may be needed.
- For immune causes, medicines that suppress the immune system may be used.
- When blood cells are being destroyed at a fast pace, the body may need extra folic acid and iron supplements to replace what is being lost.
In rare cases, surgery is needed to take out the spleen. This is because the spleen acts as a filter that removes abnormal cells from the blood.
Outlook (Prognosis)
Outcome depends on the type and cause of hemolytic anemia. Severe anemia can make heart disease, lung disease, or cerebrovascular disease worse.
When to Contact a Medical Professional
Contact your health care provider if you develop symptoms of hemolytic anemia.
References
Brodsky RA. Paroxysmal nocturnal hemoglobinuria. In: Hoffman R, Benz EJ, Silberstein LE, et al, eds. Hematology: Basic Principles and Practice. 7th ed. Philadelphia, PA: Elsevier; 2018:chap 31.
Gallagher PG. Hemolytic anemias: red blood cell membrane and metabolic defects. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 152.
Kumar V, Abbas AK, Aster JC. Hematopoietic and lymphoid systems. In: Kumar V, Abbas AK, Aster JC, eds. Robbins Basic Pathology. 10th ed. Philadelphia, PA: Elsevier; 2018:chap 12.
Version Info
Last reviewed on: 1/25/2022
Reviewed by: Todd Gersten, MD, Hematology/Oncology, Florida Cancer Specialists & Research Institute, Wellington, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
