Overview
Thrombocytopenia is the medical term for a low platelet count. Platelets (thrombocytes) are colorless blood cells that play an important role in the clotting of the blood.
Thrombocytopenia often occurs as a result of a separate disorder, such as leukemia or an immune system problem, or as a medication side effect. Thrombocytopenia may be mild and cause few signs or symptoms. In rare cases, the number of platelets may be so low that dangerous internal bleeding can occur.
Thrombocytopenia usually improves when the underlying cause is treated. Sometimes medications, surgery or a blood transfusion can help treat chronic thrombocytopenia.
Symptoms
Thrombocytopenia symptoms may include:
- Easy or excessive bruising.
- Superficial bleeding into the skin that appears as a rash of pinpoint-sized reddish-purple spots (petechiae), usually on the lower legs.
- Prolonged bleeding from cuts.
- Spontaneous bleeding from your gums or nose.
- Blood in urine or stools.
- Unusually heavy menstrual flows.
- Profuse bleeding during surgery or after dental work.
Make an appointment with your doctor if you have any signs or symptoms that worry you. Bleeding that won't stop is a medical emergency. Seek immediate help if you experience bleeding that can't be controlled by usual first-aid techniques, such as applying pressure to the area.
Possible Cause
If for any reason your blood platelet count falls below normal, the condition is called thrombocytopenia. Normally, you have anywhere from 150,000 to 450,000 platelets per microliter of circulating blood and because each platelet lives only for about 10 days, your body continually renews your platelet supply by producing new platelets in your bone marrow.
Thrombocytopenia has many possible causes.
- Trapping of platelets in the spleen The spleen is a small organ about the size of your fist located just below your rib cage on the left side of your abdomen. Normally, your spleen works to fight infection and filter unwanted material from your blood. An enlarged spleen — which can be caused by a number of disorders — may harbor too many platelets, causing a decrease in the number of platelets in circulation.
- Reduced production of platelets Platelets are produced in your bone marrow. A disease or condition that involves your bone marrow, such as leukemia and some types of anemia, could lead to a reduction in the number of new platelets produced. Viral infections, including HIV infection, may reduce your bone marrow's ability to make platelets. Toxic chemicals, chemotherapy drugs and heavy alcohol consumption also can reduce platelet production.
- Increased breakdown of platelets A number of conditions can cause your body to use up or destroy platelets more rapidly than they are produced, leading to a shortage of platelets in your bloodstream.
Examples include:
- Pregnancy Being pregnant may cause mild thrombocytopenia.
- Idiopathic thrombocytopenic purpura (ITP) In ITP, your body's immune system mistakenly identifies platelets as a threat and forms antibodies that attack them.
- Autoimmune diseases Other diseases in which your body's immune system attacks healthy tissue may cause thrombocytopenia. Examples include lupus and rheumatoid arthritis.
- Bacteria in the blood Severe bacterial infections involving the blood (bacteremia) may lead to destruction of platelets.
- Thrombotic thrombocytopenic purpura (TTP) TTP is a rare condition that occurs when small blood clots suddenly form throughout your body, using up large numbers of platelets.
- Thrombotic thrombocytopenic purpura (TTP) TTP is a rare condition that occurs when small blood clots suddenly form throughout your body, using up large numbers of platelets.
- Medications Certain medications can reduce the number of platelets in your blood by confusing the immune system and causing it to destroy platelets. Examples include heparin, quinidine, quinine, sulfa-containing antibiotics, interferon, anticonvulsants and gold salts.
Complications
Dangerous internal bleeding can occur when your platelet count falls below 10,000 platelets per microliter. Though rare, severe thrombocytopenia can cause bleeding into the brain or intestines, which can be fatal.:
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