Platelets are blood cells whose primary function is the cessation of bleeding from a ruptured or injured blood vessel. So, you can say that the role of platelets is in homeostasis. They are the fragments of cells which break off from larger cells known as megakaryocytes. The megakaryocytes reside in the bone marrow, and produce platelets in response to a protein called thrombopoietin. This protein is made by the liver, when there is a decline in the count of platelets in the circulating blood.
Platelet count may differ from individual to individual. However, the normal platelet count is generally considered to be anywhere between 150,000-450,000 platelets per micro-liter of circulating blood. Under certain circumstances, their level declines. If the count is lower than 150,000 per microliter of blood, the condition is referred to as thrombocytopenia. There can be several low platelet count causes. Read on to know about some of the causative factors, along with noticeable symptoms.
There are some potential consequences of a low blood platelet count.
- You may experience skin bleeding as the initial signal.
- You may notice tiny red dots in the skin, particularly on the lower parts of your legs. Such a condition is called petechiae.
- You may suffer from blood disorders. Even a slight injury may lead to little bruises that will spread.
- You may have bleeding gums.
- You can suffer from hematuria and melena.
- You may find bleeding quite difficult to stop. Menstrual flow too may be abnormally intense.
Medications: Certain drugs can interfere with the functioning of the immune system, and lead to low platelet count. Such drugs are quinine, heparin, gold salts, antimicrobials, anti-inflammatory, cardiac medicines, and diuretics, benzodiazepines, anti-epileptic, sulfonylurea, retinoids, iodinated contrast agents, antidepressants, and illicit drugs.
Pregnancy: During pregnancy, a woman's body produces more blood and plasma. There is a comparatively higher blood volume and lower platelet number circulating throughout the body of a pregnant woman. The platelets are spread apart and more diluted. According to studies, about 5% of expectant mothers develop mild to moderate thrombocytopenia, particularly when they are close to parturition.
Autoimmune Diseases: There are some autoimmune diseases wherein the immune system of your body destroys its own platelets. An example of such an autoimmune disease is known as idiopathic thrombocytopenia purpura (ITP). In majority of the cases, your immune system is believed to cause ITP. Under normal conditions, your immune system works to fight infections and diseases. However, when you suffer from ITP, your immune system takes the platelets as foreign substances, attacks, and destroys them. There are some more examples, like lupus and rheumatoid arthritis.
Hemolytic Uremic Syndrome: HUS is a medical condition which is characterized by the breakup of erythrocytes (red blood cells) and kidney failure. It involves clumping of platelets in the small blood vessels of the kidneys, resulting in reduced blood flow or ischemia. Such a condition can cause kidney failure. The partial blockage of the blood vessels may even lead to hemolysis, which is the destruction of erythrocytes. Several conditions, like E. Coli, Shigella bacteria, tumors, drugs, pregnancy, and systemic lupus erythematosus, may cause HUS.
Thrombotic Thrombocytopenia Purpura: The medical condition, wherein small blood clots get suddenly formed throughout the body, is called thrombotic thrombocytopenia purpura (TTP). Since blood clotting requires platelets, this condition is characterized by sudden fall in the blood platelet count. TTP is a life-threatening disease, and is symptomized by breakup of erythrocytes, fever, renal abnormalities, aphasia, convulsions, and blindness.
The condition of low platelet count is diagnosed by a complete blood count (CBC). It includes a count of platelets in the blood. A blood smear may be performed by the clinician to double-check the number. Effective medical treatment is available for this condition, usually depending upon the cause. Hence, correct and timely diagnosis is a must.