What is hemolysis?
Hemolysis is the destruction ofred blood cells(erythrocytes). Your red blood cells are an essential part of your blood. They carry oxygen from the lungs to tissues throughout the body. Your body uses this oxygen to create the energy it needs to perform essential functions. Red blood cells also carry carbon dioxide from your tissues back to your lungs for you to exhale.
Your body is constantly destroying old or damaged red blood cells and creating new ones to replace them. This constant cycle of destruction and creation ensures that you have enough red blood cells. Sometimes red blood cells are destroyed too quickly before your body has time to replace them.
The process of red blood cell destruction - including the premature destruction of red blood cells - is called hemolysis. Too few red blood cells due to hemolysis causes a condition known ashemolytic anemia.
Why does hemolysis occur?
The destruction of red blood cells normally makes room for new, healthy red blood cells. The average red blood cell lives 120 days. As old cells age, they release specific signals that lead to the organized destruction of the aging cell in your spleen. YourspleenIt is an organ on the left side of the abdomen that helps clean out old and damaged cells.
Your body makes new blood cells in the spongy tissue inside your bones called bone marrow. New red blood cells are released into your bloodstream.
Problems related to the structure or components of a cell sometimes shorten its lifespan. Outside factors can also damage red blood cells, causing them to die before your body has time to replace them.
What are the types of hemolysis?
There are two types of hemolysis. Their names indicate where hemolysis occurs.
- Extravascular Hemolysisinvolves the destruction of red blood cells that occurs outside your blood vessels.blood veinsThese include veins, arteries and capillaries. Your spleen is the most common site of extravascular hemolysis. How blood filters through your spleenWhite blood cellsso-called macrophages locate and destroy old or damaged red blood cells.
- Intravasale Hämolyseinvolves the cellular destruction that occurs in blood vessels. In intravascular hemolysis, the destroyed cell parts circulate in the blood.
symptoms and causes
What causes hemolysis?
Hemolysis has several causes.
defective red blood cells
Structural irregularities in a red blood cell can cause it to be destroyed too soon. Many of the structural problems that cause hemolysis are inherited.
Conditions with structural defects of red blood cells include:
- unstable hemoglobins:sickle cell anemiaEThalassemia.
- enzymatic deficiency:G6PD deficiencyEPyruvate Kinase Deficiency.
- membrane defects:hereditary spherocytosisEhereditary elliptocytosis.
Diseases related to the immune system
autoimmune hemolytic anemia(AIHA) is a rare condition in which yourimmune systemattacks your red blood cells. As a result, you have very few of them. Types of autoimmune hemolytic anemia include:
- cold agglutinin disease(cold autoimmune hemolytic anemia).
- Warm agglutinin disease (warm autoimmune hemolytic anemia).
Underlying conditions can cause autoimmune hemolytic anemia. Mycoplasma pneumonia, lymphoma, leukemia, lupus, and rheumatoid arthritis are just a few conditions that can cause the immune system to attack red blood cells.
Other non-autoimmune diseases:
- Paroxysmal cold hemoglobinuria.
- Paroxysmal Nocturnal Hemoglobinuria.
Parasites, viruses, and bacteria that enter your body can damage your red blood cells, causing them to break down before your body can make replacements. The most well-known infectious cause of hemolysis is malaria, in which a parasite attacks red blood cells.
Infectious causes of hemolysis include:
- Human immunodeficiency virus (HIV).
Some medications can cause the immune system to attack red blood cells, destroying them prematurely. This is called drug-induced immune hemolytic anemia (DIHA). IHAD is extremely rare.
Medications that can cause hemolysis include:
Problems during pregnancy can cause red blood cells to break down too early. Pregnancy complications related to hemolysis include:
- HELLP syndrome.
- Pre eclampsia.
Medical devices and treatments
Although rare, hemolysis can occur as your body adjusts to a new medical device or treatment, including:
- cardiopulmonary bypass machine.
- heart valve replacement.
- Other cardiac devices used to treat cardiac shock, including intra-aortic balloon pumps and Impella devices.
- blood transfusions.
poisons and toxins
Poisons or toxins can damage red blood cells and cause hemolysis. Harmful substances that can cause hemolysis include:
- cobra venom.
Any condition that causes your spleen to work overtime (Hyperesplenism) can cause hemolysis.
Extremely high blood pressure can cause red blood cells to break down as they travel through blood vessels and organs.
What are the signs and symptoms of hemolysis?
Symptoms depend on how low your red blood cell supply is. If your number is not very low, you may not notice any symptoms. Symptoms are usually related to a lack of oxygen because you don't have enough red blood cells to carry oxygen to your body's cells and tissues.
- Pale skin.
- palpitations (Tachycardia).
- shortness of breathe (Dyspnea).
- yellowing of the skin and whites of the eyes (jaundice).
- enlarged spleen (splenomegaly).
Some symptoms are unique to the specific condition causing the hemolysis. For example, cold agglutinin disease, a form of autoimmune hemolytic anemia, can cause decreased blood flow to the fingers or toes (Raynaud's Phenomenon).
diagnosis and test
What tests are done to check for problems related to hemolysis?
A doctor will take a blood draw to check for problems related to hemolysis. You can have any of the following tests to see if your blood cell count is low due to hemolysis.
- Complete blood count (CBC):Acomplete blood countprovides valuable information about all your blood cells, including red blood cells. It provides information about levels of hemoglobin (an essential protein in the blood) and hematocrit (the amount of space red blood cells occupy in the blood).
- Reticulocyte count:Areticulocyte countis part of a blood count. It tells you how many reticulocytes (immature red blood cells) you have. You can have elevated reticulocytes with hemolysis because your body increases production of new red blood cells to replace destroyed ones.
- Peripheral blood smear:Aperipheral blood smearit shows abnormalities in your blood cells, such as an unusual size or shape. Abnormalities can cause macrophages to destroy red blood cells.
- Lactatodesidrogenase (LDH):LDHit is an enzyme in your red blood cells. Elevated LDH in the blood can indicate that red blood cells are being destroyed faster than normal.
- Haptoglobin tests:Haptoglobin is a protein that binds to hemoglobin. Haptoglobin levels drop when large amounts of hemoglobin are released into the blood (as in hemolysis).
- Unconjugated bilirubin: bilirubinit is formed when the hemoglobin in red blood cells is broken down. Elevated bilirubin in the blood can indicate that large amounts of red blood cells are being destroyed.
- Direct Coombs Test:Adirect Coombs testcan detect antibodies that attach to your red blood cells and destroy them prematurely.
A healthcare professional can also do the following:urinalysisCheck for signs of blood or bilirubin in the urine (pee) that could indicate hemolytic anemia.
management and treatment
How is hemolysis treated?
Your treatment will depend on what's causing your hemolysis and the severity of your symptoms. Treatments may include dietary supplements, medications, surgery, blood transfusions, etc. Discuss your treatment options with your doctor based on your diagnosis.
A note from the Cleveland Clinic
Your body is constantly working to make sure you have the right amount of red blood cells. Infections, hereditary diseases, external factors, etc. can get in the way of that work by destroying red blood cells too soon. As a result, you may have low red blood cells and develop hemolytic anemia. Fortunately, many causes of hemolysis are treatable. Once your doctor can determine what's causing your hemolysis, he or she may recommend treatments to bring your red blood cell count back into the normal range.