Platelet Count

What is a Platelet Count?

Blood consists of numerous components that are important for health, including platelets.

Platelets are tiny fragments, also known as thrombocytes, critical for blood clotting. They are like the body’s natural plasters because they work to stop bleeding. Platelets are made in the bone marrow, the spongy tissue inside bones, by cells called megakaryocytes and circulate in blood, ready to travel to a damaged site to initiate clotting.

When an injury occurs, a reaction happens in the blood vessel wall, activating platelets and specific proteins called clotting factors in the blood. Platelets and clotting factors work in tandem to slow down and stop blood from leaking out of the vessel.

Here is a closer look at how platelets stop bleeding:

• After an injury, the blood vessel wall contracts to reduce blood flow and loss.
• Platelets travel to the injury site, after being attracted by the exposed collagen, and begin plugging the leak.
• Cells lining the blood vessel wall express a glycoprotein called von Willebrand factor which acts like a glue, encouraging platelets to stick to the collagen and each other.
• Platelets undergo a structural transformation, changing from discs to spheres. This activates the platelets and they begin to secrete substances which signal other platelets to join them.
• Within seconds, the platelet clump forms a plug in the damaged blood vessel, temporarily closing the wound.
• A stronger clot is needed to repair the damaged vessel permanently, so clotting factors convert a protein called fibrinogen into fibrin. Fibrin acts like a needle and thread, weaving in and out of the platelet plug, creating a strong barrier.
• The fibrin barrier encourages new tissues to grow, prompting the healing process. Once the wound is completely healed, the fibrin clot dissolves and leaves the body^[1].

When is a Platelet Count Needed?

A platelet count blood test quantifies how many platelets are in circulation. It may be requested, if someone wants to check their platelets are working correctly, and if they have symptoms of a blood clotting disorder or an unexplained blood clot^[2].

How to Check Your Platelet Count?

A platelet count is usually part of a full blood count. The test will show the size, number and shape of platelets. At-home platelet count tests are available and you can explore our range of at-home blood tests or even create your own.

What is a Normal Platelet Count?

The normal reference range for a platelet count is 140 – 400 x 10*9/L, however, this can vary according to the testing laboratory. So, there are approximately 140,000 to 400,000 platelets in every microlitre of blood.

What Causes a Low Platelet Count?

If the body doesn’t produce enough platelets, it can cause thrombocytopenia. Thrombocytopenia causes the bone marrow to produce too few platelets, leading to bruising and excessive bleeding which can take a long time to slow down or stop.

There are several common causes of thrombocytopenia, such as:

• Autoimmune conditions: Primary autoimmune thrombocytopenia (ITP) is caused by antibodies attacking platelets causing destruction, while conditions like lupus and rheumatoid arthritis cause secondary ITP.
• Medications: Certain drugs and medicines can suppress platelet production, like anticoagulants, some bipolar disorder treatments, and antimalarials.
• Infections: Viruses like HIV, hepatitis C, mumps and rubella as well as sepsis, helicobacter pylori and malaria can induce thrombocytopenia.
• Nutrient deficiencies: Not getting enough vitamin B12, folate, or copper in the diet can cause low platelet numbers. These micronutrients are important for platelet production and maintenance^[3].
• Chronic alcohol intake: Alcohol stops the proper functioning of platelets and in people who drink excessive amounts, low platelet counts are not uncommon^[4].
• Pregnancy: Thrombocytopenia is the second most common blood disorder in pregnancy after anaemia, affecting up to 11% of pregnancies^[5].

A low platelet count means excessive or prolonged bleeding is likely to occur if a blood vessel becomes damaged. Without sufficient platelet numbers, blood may not clot properly causing symptoms, such as bruising and blood loss.

Symptoms of a Low Platelet Count

• Prolonged bleeding even from small injuries or cuts
• Frequent nosebleeds or bleeding gums
• Heavy periods in women and girls
• Small, red spots under the surface of the skin caused by leaking blood vessels called petechiae
• Red, purple, or brown/yellow spots caused by bleeding under the skin called purpura
• Blood in urine or stools^[6]

What Causes a High Platelet Count

A high number of platelets circulating in the blood can be caused by one of two conditions:

• Thrombocythemia: A high platelet count that is not caused by another condition. It is sometimes referred to as primary or essential thrombocythemia.
• Thrombocytosis: More common than thrombocythemia, thrombocytosis explains a high platelet count caused by another condition. It is also known as secondary or reactive thrombocytosis^[7].

Some of the conditions that cause a high number of circulating platelets include:

• Chronic inflammation
• Iron deficiency
• Red blood cell destruction (haemolysis)
• Systemic infections
• Medications (corticosteroids)
• Some cancers
• Surgery
• Trauma^[7]

Symptoms of a High Platelet Count

Some people won’t know they have a high platelet count until they have a routine blood test. Thrombocythemia is more likely to cause symptoms associated with blood clots and bleeding.
Blood clots are most likely to form in the brain, hands, and feet. In the brain, blood clots may cause chronic headaches or dizziness but in the most severe cases, they may cause mini-strokes (transient ischaemic attacks) or a stroke.

Blood clots in the hands and feet can cause numbness and redness, or a burning or throbbing pain in the palms or soles of the feet.

Some other signs of a blood clot are:

• Slurred speech
• Confusion
• Shortness of breath or difficulty breathing
• Feeling sick
• Weakness, especially down one side of the body
• Chest pain
• Migraines
• Seizures^[9]

Bleeding

Some people with high platelet counts may experience bleeding, such as nose bleeds, bleeding gums, or blood in their poo. Bleeding happens when thrombocythemia or thrombocytosis uses up all the circulating platelets so there aren’t enough to plug cuts or other breaks in blood vessel walls.

Can You Manage Platelet Levels?

There are certain lifestyle choices you can make to help maintain a healthy platelet count and support their normal production.

Diet

Eating foods that contain certain nutrients associated with good platelet health and function may help to maintain their numbers within normal levels in your blood. A healthy, balanced, and nutritious diet will benefit your health and well-being.

Reduce alcohol intake

Because increased alcohol intake is associated with reduced platelet function and count, keeping your alcohol intake to a minimum or within the recommended guidelines will help promote platelet health.

Exercise appropriately

If you have a low platelet count, you may need to adjust your training program to suit. You might consider gentle exercises that do not involve resistance, such as stretching or walking.

If you have been diagnosed with thrombocytopenia, you should be cautious when exercising to prevent the risk of bleeding^[10].

Written by Leanne Edermaniger

Based in the UK, Leanne specialises in writing about health, medicine, nutrition, and fitness.

She has over 5 years of experience in writing about health and lifestyle and has a BSc (hons) Biomedical Science and an MSc Science, Communication and Society.