Low platelet count or thrombocytopenia, as it is medically termed, is when the platelet count production decreases or keeps getting depleted. Platelets are responsible for clotting of blood and cause serious damage if low in number. The normal platelet count in blood ranges from 150,000 to 400, 000 per milliliter of blood, and has a life of 10 days. Thus it has to be continuously replenished, and is synthesized in the bone marrow.
Sometimes the test for low platelet count can give false results. This could be due to the aggregation of platelets cause by proteins used for the test. This is known as artifactual (caused by a false result) thrombocytopenia can be avoided by repeating the test a few times with several methods using different chemicals.
Lower rate of production of platelets is a cause of thrombocytopenia. This can be due to any condition, like anemia that affects the bone marrow. Leukemia also adversely affects production of new platelets, as do infections caused by viruses (example HIV). Cancers of the bone marrow and certain drugs used to treat cancer also cause low platelet count.
Low platelets can also be a result of a hereditary disease, called congenital thrombocytopenia. The symptoms of this condition vary in different individuals. Other inherited diseases can also be responsible for low platelet count due to symptoms like increased bleeding.
If platelets are lost or die rapidly, it could lead to thrombocytopenia. This could be due to multiple factors like pregnancy, autoimmune diseases, bacterial infection, blood poisoning, or other illnesses associated with the immune system. Sometimes, due to causes unknown, antibodies produced against platelets can cause them to aggregate thus reducing their concentration in blood.
Patients with enlarged spleen can hold a lot of platelets thus reducing the count from normal circulation. Dilution of platelets can also occur after blood transfusion, if the patients receive blood which has a low platelet count.
Symptoms that indicate a low platelet count include heavy bleeding from the nose, blood in the urine and stools, dizziness, bruising, vaginal bleeding and bleeding from gums during brushing. In serious cases, bleeding can also occur in the eye, or internally within the brain or gut. Treatment of this condition depends highly on the cause of low platelets. If the low platelet count is a temporary occurrence due to a drug or infection, it can be treated by replacing the causative drug or administering antibiotics for the infection. In case of heavy bleeding, the patient might have to be given a blood transfusion.