Platelets are tiny cells in the bone marrow. Platelets are very important because they prevent bleeding by forming clots and blocking blood vessels if they are damaged.
The normal platelet count ranges from 150,000 to 450,000 per microliter (μL) of blood. Too many or too few platelets can lead to complications.
Learn more about normal platelet count ranges.
What are platelets?
Platelets are blood cells that help prevent bleeding. These cells are made in the bone marrow. When a blood vessel is damaged, platelets are activated to clump together and form a clot that closes the wall of the blood vessel to stop or prevent bleeding.
What is the normal platelet count?
The normal platelet count is between 150,000 and 450,000 / μL of blood.
What does an abnormal platelet count mean?
An abnormal platelet count means that there are too many or too few platelets in the blood.
Elevated platelet count
A platelet count of more than 450,000 / μL is called thrombocytosis. It can also be classified as primary or secondary thrombocytosis, which are caused by the bone marrow making too many platelets:
- In primary thrombocytosis , there is a natural abnormality (such as a genetic mutation) in the cells of the bone marrow that produce platelets. So too many platelets are produced all the time.
- With secondary thrombocytosis , there is no problem with the cells that make platelets. They produce too many platelets as a normal response to signals they receive from another process elsewhere (such as iron deficiency or inflammation).
Symptoms of thrombocytosis can include abnormal bruising, bleeding, or stroke-like symptoms. Very often there are no symptoms. Too many platelets can cause blood clots. In fact, this can lead to acquired von Willebrand disease , in which platelets cannot properly interact with the wall of blood vessels at the site of injury. If you don't seal the injury site, bleeding occurs.
Low platelet count
A platelet count of less than 150,000 / μL is considered low and is called thrombocytopenia.
Platelet counts can decrease for several reasons:
- Bone marrow dysfunction: The bone marrow may not work properly and may not make enough platelets.
- Enlarged spleen: Platelets may be in the enlarged spleen and not circulate through the blood vessels.
- Liver disease: This can cause platelet dysfunction and an enlarged spleen.
- Damage to the immune system: Sometimes the immune system misinterprets platelets as foreign and destroys them.
- Medications: These may include chemotherapy, antibiotics, anticonvulsants, and blood thinners.
Symptoms of thrombocytopenia can include:
- Bleeding, such as from the gums when brushing the teeth or in the stool.
- Heavy menstrual cycles
- Petechiae, small, red, pointed bleeding spots that may look like a rash
Too few platelets can cause bleeding because there are not enough platelets to clot and repair the blood vessel walls if they are damaged.
How is the platelet count determined?
Your platelet count is checked using a blood test called a complete blood count, or CBC. A blood sample is taken to perform a complete blood count. This blood sample is then put into a machine to count all types of cells in the blood. This includes an estimate of the size of the cells, as well as their number. Platelet size is called MPV or mean platelet volume.
If the MPV is elevated, it means that the platelets are higher than usual. Elevated MPV can be detected in the following cases:
A decrease in MPV means there are fewer platelets than usual. Reduced MPV can be found due to:
Frequently asked questions
What is the normal platelet count?
The normal platelet count is between 150,000 and 450,000 platelets / μL of blood.
What is the difference between normal platelet count in men and women?
Women tend to have more platelets than men, possibly due to hormonal differences and menstrual cycles. No differences were found in MPV.
What is the normal number of platelets in children?
The normal platelet count in children is similar to the normal platelet count in adults: 150,000 to 450,000 / μL.
Get the word of drug information
If you are experiencing symptoms such as bleeding or bruising and are concerned about your platelet count, be sure to speak with your doctor about your concerns. A simple blood test can be done to make sure they are normal, and if not, further evaluation may be required.