What is PC?

Platelet count (PC) is also known as Thrombocyte count, Platelet count test (PLT), Platelet distribution width (PDW), and Mean platelet volume (MPV). This test determines the number of platelets in the blood. The platelets are also known as thrombocytes which are tiny fragments of cells. They play an important role in the process of normal blood clotting.

Why is PC done?

The platelet count is done:

• As a part of routine complete blood count
• In case of signs and symptoms of bleeding disorders such as easy bruising and prolonged bleeding
• To monitor platelet count in case of conditions showing low platelet count such as dengue fever
• To detect bone marrow disease

What does PC Measure?

The platelet count measures the number of platelets present in the blood. Platelets are also known as thrombocytes which are tiny fragments of cells. These are formed from large cells which are found in the bone marrow known as megakaryocytes. After the platelets are formed, they are released into the blood circulation.

Whenever there is an injury to a tissue or blood vessel, bleeding starts. At this point, platelets help in stopping the bleeding in three ways:

• The platelets will adhere to the injury site
• The platelets will accumulate at the injury site
• The platelets will release chemical compounds which stimulate the gathering of other platelets

With these steps, a loose platelet connection forms at the site of injury. This process is known as primary hemostasis. The activated platelets start to support the coagulation cascade which involves a series of steps that includes the sequential activation of clotting factors. This process is known as secondary hemostasis which results in the formation of fibrin strands that knit through the loose platelet connection to form a fibrin net. After that, the connection is compressed to form a stable clot so that it remains in place until the injury heals. Once the injury is healed, other factors come into play and break it down so that it gets removed.

In case the platelets are not sufficient in number or are not functioning properly, a stable clot might not form. These unstable clots can result in an increased risk of excessive bleeding.

Is there any preparation required before the test?

Inform the doctor about the medications you may be taking. No other specific preparations are usually required before this test.

How is the blood sample taken?

The healthcare provider takes a blood sample from the arm. The site from where the blood is to be withdrawn is cleaned with a swab of rubbing alcohol. This is then followed by inserting a small needle which has a tube attached to it for collecting blood. Once the sufficient blood for analysis is withdrawn, the needle is removed. The site is then covered with a gauze pad.