What is Platelet Count and What are causes for Elevated Platelet Count?

Platelets are tiny fragments of precursor cells called megakaryocytes. Platelets are anucleated (without nucleus) and play a pivotal role in stopping of bleeding in our body. Whenever, there is an injury to our body, resulting in damage to blood vessels, these platelets get activated and reach the site of injury. They bind together forming a meshwork of sorts and plug the injured blood vessel wall.

Platelets can be counted on cell counters (automated machines) and sometimes by a manual method using a microscope. A platelet count of 1,50,000 to 4,50,000 per µL (microlitre) of blood is considered normal for a healthy adult. Although the ranges are dependent on a variety of factors and can be slightly different from lab to lab, anything within this range can be considered as normal platelet count. Counts lesser than 1,50,000 are called thrombocytopenia and counts greater than 4,50,000 are called thrombocytosis.

Causes for Thrombocytosis

There are 2 types of thrombocytosis – primary thrombocytosis (usually called Essential Thrombocythemia), secondary thrombocytosis

In primary thrombocytosis, no probable cause for the rise in platelets exist but in secondary thrombocytosis, one or more of the conditions like anaemia, cancer, inflammation, infection, etc. exists. This means that once the associated condition is treated successfully, the platelet count will also normalise in secondary thrombocytosis.

Signs and Symptoms of Thrombocytosis

Spontaneous blood clots in the blood vessels of arms & legs may cause fatigue, pain, and cramps in the extremities. Clots in the head may lead to light headedness, headaches, vision changes, and even stroke. Blood clots in the chest region may cause chest pain, heaviness, shortness of breath, sweating, and even heart attacks. Very rarely, when the platelet count is >10 lakh per µL, it may manifest as bleeding from the nose, mouth, or gums, bloody stool, and easy bruising.

Platelet count can be checked through a simple blood test like Hemogram or Complete blood count or just a platelet count. A regular monitoring will help in the early diagnosis and treatment of the underlying condition.