Platelets are a component of blood that is important for clotting and bleeding. They are made in the bone marrow with about 2/3 of all platelets being found in the blood and the balance 1/3 present in the spleen. Normally there are between 150,000 and 450,000 platelets per microliter of blood. Whenever the levels of platelets in the blood fall below these levels it is known as thrombocytopenia.
There are many possible causes of a low platelet count in adults.
Platelets may get trapped in the spleen. This is a small organ on the left side of the abdomen that works to fight infection as well as filter impurities from the blood. Many disorders can cause an enlargement of the spleen resulting in too many platelets being trapped inside, thus reducing the number of platelets in circulation.
A reduction in platelet production can also reduce platelet count. Any disease that affects the bone marrow where platelets are produced, including leukemia and some types of anemia, can reduce platelet count. Viral infections such as HIV infection, toxic chemicals such as those used in chemotherapy and heavy intake of alcohol are some of the other causes of low platelet production.
There are several other conditions that cause a lowered platelet level.
What causes a low platelet count in these cases is the rapid destruction of platelets. The bone marrow is unable to replace the destroyed cells in time and this leads to a shortage of platelets in the blood. Some of these conditions include:
- Autoimmune diseases such as lupus and rheumatoid arthritis
- Idiopathic thrombocytopenic purpura (ITP)
- Thrombotic thrombocytopenic purpura (TTP)
- Bacterial infections of the blood
- Hemolytic uremic syndrome
- Side effects of some medications such as heparin, quinine, quinidine, interferon, anticonvulsants and antibiotics containing sulfa
Causes of low platelet count in children will include any disease that affects the bone marrow resulting in a decrease in platelet production. Some of these causes include:
- Certain types of leukemia that shut down production of platelets in the bone marrow
- Viruses which cause mumps and others such as Epstein-Barr which causes mononucleosis and parvovirus can all cause a decrease in platelet production in the bone marrow
- Chemotherapy drugs used to treat cancer can also cause a decrease in platelet production
Submitted by N on May 16, 2012 at 01:40