Fast facts about platelets1

While you may not know much about platelets, they are very important. Platelets are tiny blood cells that help your body form clots to stop bleeding. They’re sometimes called thrombocytes but, interestingly, that name is not accurate.That’s because the ‘cyte’ part means ‘cell’ – and platelets are in fact tiny bits of cells.They are only about 3 thousandths of a millimetre across.

Usually, the platelet count range is 150,000 - 450,000 per microlitre (a thousandth of a milllilitre) of blood.They last for about 10 days before being broken down and recycled.

What do platelets do?1

When you get injured, it’s important to seal up any bleeding quickly, to keep your blood and its cells in, and infections out.Your body has an impressive response system to make sure this happens. Firstly, the damaged area tightens itself to reduce blood loss. Nearby platelets are then activated and become spiky and sticky.They stick together,and to the damaged tissue, forming a temporary plug (see figure 1).

The activated platelets release chemical signals that call other platelets to join in the action.The signals also tell proteins in your blood to form a mesh. This mesh catches red blood cells and forms what you know as a clot.

The platelets’ job doesn’t stop there – they then produce chemicals called growth factors that send signals to other cells to help heal the damaged tissue.

Where do platelets come from?1

Platelets are made in the red area of your bone marrow, along with white blood cells (which make up your immune system and fight infection) and red blood cells.

Stem cells in the bone marrow reproduce and turn into very large cells called megakaryoctyes.These then break down into bits that form the platelets. Once they are released into your blood, about a third of the platelets travel to your spleen, where they are stored in case you get injured. Your spleen also contains cells that break down unwanted material in your blood, including worn-out platelets.

How are platelets affected by Gaucher disease?2

Bone marrow and the spleen are both affected by Gaucher disease.This can lead to not enough platelets being created and too many being destroyed.This is called thrombocytopenia,and can contribute to you being easily bruised, or bleeding a lot even from a small injury.


1. Anatomy and Physiology. OpenStax at Rice University. Published 25 April 2013. ISBN-13: 978-1-947172-04-3. Available at September 2019

2. Cappellini MD et al. European Oncology & Haematology. 2018;14:50–56.