One example of this type of autoimmune disease is immune thrombocytopenia ITP. ITP is a bleeding disorder in which the blood doesn't clot as it should. An autoimmune response is thought to cause most cases of ITP. Normally, your immune system helps your body fight off infections and diseases. But if you have ITP, your immune system attacks and destroys its own platelets. Why this happens isn't known.
ITP also may occur if the immune system attacks your bone marrow, which makes platelets. A reaction to medicine can confuse your body and cause it to destroy its platelets.
Quinine is a substance often found in tonic water and nutritional health products. Heparin is a medicine commonly used to prevent blood clots. But an immune reaction may trigger the medicine to cause blood clots and thrombocytopenia.
This condition is called heparin-induced thrombocytopenia HIT. HIT rarely occurs outside of a hospital. In HIT, the body's immune system attacks a substance formed by heparin and a protein on the surface of the platelets. This attack activates the platelets and they start to form blood clots. Blood clots can form deep in the legs deep vein thrombosis , or they can break loose and travel to the lungs pulmonary embolism.
A low platelet count can occur after blood poisoning from a widespread bacterial infection. A virus, such as mononucleosis or cytomegalovirus, also can cause a low platelet count. Platelets can be destroyed when they pass through man-made heart valves, blood vessel grafts, or machines and tubing used for blood transfusions or bypass surgery.
About 5 percent of pregnant women develop mild thrombocytopenia when they're close to delivery. The exact cause isn't known for sure. Some rare and serious conditions can cause a low platelet count. TTP is a rare blood condition. It causes blood clots to form in the body's small blood vessels, including vessels in the brains, kidneys, and heart. DIC is a rare complication of pregnancy, severe infections, or severe trauma. Tiny blood clots form suddenly throughout the body.
Usually, one-third of the body's platelets are held in the spleen. If the spleen is enlarged, it will hold on to too many platelets. This means that not enough platelets will circulate in the blood. An enlarged spleen often is due to cancer or severe liver disease, such as cirrhosis sir-RO-sis. Cirrhosis is a disease in which the liver is scarred.
This prevents it from working well. An enlarged spleen also might be due to a bone marrow condition, such as myelofibrosis MI-eh-lo-fi-BRO-sis. With this condition, the bone marrow is scarred and isn't able to make blood cells. People who are at highest risk for thrombocytopenia are those affected by one of the conditions or factors discussed in "What Causes Thrombocytopenia? Whether you can prevent thrombocytopenia depends on its specific cause.
Usually the condition can't be prevented. However, you can take steps to prevent health problems associated with thrombocytopenia. For example:.
Mild to serious bleeding causes the main signs and symptoms of thrombocytopenia. Signs and symptoms can appear suddenly or over time. Mild thrombocytopenia often has no signs or symptoms. Many times, it's found during a routine blood test.
Check with your doctor if you have any signs of bleeding. Severe thrombocytopenia can cause bleeding in almost any part of the body. Bleeding can lead to a medical emergency and should be treated right away. External bleeding usually is the first sign of a low platelet count. Purpura are purple, brown, and red bruises. This bruising may happen easily and often. Petechiae are small red or purple dots on your skin.
Purpura and petechiae in the skin. The photograph shows two types of bruising that are often seen with DIC. The larger red, brown, and purple dots are purpura and the smaller red and purple dots are petechiae.
Heavy bleeding into the intestines or the brain internal bleeding is serious and can be fatal. Signs and symptoms include:. Your doctor will diagnose thrombocytopenia based on your medical history, a physical exam, and test results.
A hematologist also may be involved in your care. This is a doctor who specializes in diagnosing and treating blood diseases and conditions.
Your doctor will do a physical exam to look for signs and symptoms of bleeding, such as bruises or spots on the skin. He or she will check your abdomen for signs of an enlarged spleen or liver. However, it can sometimes cause blood clots.
These blood clots can, in turn, cause [ 48 ]:. If your platelets are high, they may falsely elevate blood potassium and phosphorus levels [ 49 ]. Causes listed below are commonly associated with a high platelet count. Inflammatory disorders, such as rheumatoid arthritis or inflammatory bowel disease IBD , are the most common causes of increased platelet counts [ 50 , 51 , 52 ]. Some infectious diseases can increase your platelet count. Exercise and physical exhaustion can temporarily increase your platelet count [ 55 , 56 ].
Recovery from blood loss after surgery or injury can increase platelet counts [ 57 , 58 ]. High platelet count is often found in iron-deficiency anemia. Drinking alcohol initially decreases your platelet count. However, when the alcohol is gone from your system the body overcompensates leading to a rebound effect and thrombocytosis high platelet count [ 60 , 61 , 62 ]. This rebound effect is associated with heavy alcohol drinking and is not observed with moderate red wine consumption, for example [ 63 ].
Birth control pills oral contraceptives and estrogen therapy can both increase platelet count [ 64 , 65 ]. Having your spleen removed splenectomy can significantly increase your platelet count [ 48 , 66 ]. Primary thrombocythemia is a rare bone marrow disorder in which the bone marrow produces too many platelets [ 67 , 68 ]. Various types of cancer can increase platelet counts e.
Avoid overindulging in alcohol. As mentioned above, heavy alcohol drinking causes fluctuations in your platelet count. First platelets will decrease, then after withdrawal, they will increase above the normal range [ 60 , 61 , 62 ]. In addition, you can check your iron levels. Make sure your diet is well balanced and contains all the necessary nutrients in adequate amounts [ 59 ].
Low Platelet Count Thrombocytopenia. The body produces more platelets during and following an injury. However, because platelets cause blood clotting, they can also cause dangerous blood clots in the arms or legs.
The blood clot may break off or travel to another area of the body. The risk of a blood clot is higher in people who are confined to bed by illness or who cannot move their limbs. Someone who has an elevated platelet count because of a recent injury but who must remain in bed may need monitoring to reduce the risk of blood clots as a result. Some temporary conditions can cause a higher than normal platelet count. A doctor may order a retest a few days or weeks later when this happens.
Some common reasons that platelets are temporarily elevated include:. A low platelet count can make it difficult for the blood to clot, putting a person at risk of excessive bleeding. The cause may be due to an inherited tendency to not produce enough platelets, but the cause may also be unknown. In other cases, it is due to an underlying medical condition. If the blood platelet count falls below 20, per mcL, a person can begin bleeding spontaneously.
People who experience spontaneous bleeding may require a blood transfusion. Low platelet count increases the risk of death in people who have recently experienced a traumatic injury.
Platelet count also tends to decline with age. A platelet count that is lower than it once was, or that is on the lower end of normal, may not be a cause for concern in an older adult—especially if there are no other symptoms. Changes in platelet count may mean that a person has a chronic illness or that there is an issue with the bone marrow. It is generally not possible, however, to diagnose a medical condition based on platelet count alone. Edited by JO Armitage.
Philadelphia, Current Medicine, From Tefferi A, Li C. Platelets are cell fragments that function in the clotting system. Thrombopoietin helps control the number of circulating platelets by stimulating the bone marrow to produce megakaryocytes, which in turn shed platelets from their cytoplasm.
Thrombopoietin is produced in the liver at a constant rate and its circulating level is determined by the extent to which circulating platelets are cleared, and possibly by bone marrow megakaryocytes. Platelets circulate for 7 to 10 days. About one third are always transiently sequestered in the spleen. However, the count can vary slightly according to menstrual cycle phase, decrease during near-term pregnancy gestational thrombocytopenia , and increase in response to inflammatory cytokines secondary, or reactive, thrombocytosis.
Platelets are eventually destroyed by apoptosis, a process independent of the spleen. An abnormal increase in platelets thrombocythemia Essential Thrombocythemia Essential thrombocythemia ET is a myeloproliferative neoplasm characterized by an increased platelet count, megakaryocytic hyperplasia, and a hemorrhagic or microvascular thrombotic tendency See also Overview of Myeloproliferative Neoplasms.
Any of these conditions, even those in which platelets are increased, may cause defective formation of hemostatic plugs and bleeding. The risk of bleeding is inversely proportional to the platelet count and platelet function see table Platelet Count and Bleeding Risk Platelet Count and Bleeding Risk Platelets are cell fragments that function in the clotting system.
Thrombopoietin helps control the number of circulating platelets by stimulating the bone marrow to produce megakaryocytes, When platelet function is reduced eg, as a result of uremia, or use of nonsteroidal anti-inflammatory drug [NSAID] or aspirin , the risk of bleeding increases. Essential thrombocythemia Essential Thrombocythemia Essential thrombocythemia ET is a myeloproliferative neoplasm characterized by an increased platelet count, megakaryocytic hyperplasia, and a hemorrhagic or microvascular thrombotic tendency There are many causes, including acute infection, chronic inflammatory disorders eg, rheumatoid arthritis Rheumatoid Arthritis RA Rheumatoid arthritis RA is a chronic systemic autoimmune disease that primarily involves the joints.
RA causes damage mediated by cytokines, chemokines, and metalloproteases. TB most commonly affects the lungs. Symptoms include productive The lungs and lymphatic system are most often affected, but Heme iron, contained mainly in animal products, is absorbed much better than nonheme iron eg, in plants and Reactive thrombocytosis is not typically associated with an increased risk of thrombosis or bleeding. Causes of thrombocytopenia can be classified by mechanism see table Classification of Thrombocythemia Classification of Thrombocytopenia Platelets are cell fragments that function in the clotting system.
A large number of drugs may cause thrombocytopenia Drug-induced immunologic destruction Platelet destruction can develop because of immunologic causes viral infection, drugs, connective tissue or lymphoproliferative disorders, blood transfusions or nonimmunologic causes sepsis Pregnancy gestational thrombocytopenia Pregnancy Platelet destruction can develop because of immunologic causes viral infection, drugs, connective tissue or lymphoproliferative disorders, blood transfusions or nonimmunologic causes sepsis Typically, it is chronic in adults, but it is usually acute and self-limited in children.
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