Platelets are vital for blood clotting and wound healing. However, having either too few or too many platelets can cause health issues. Keep reading to learn more about platelets, underlying causes of abnormal platelet counts, and how to improve them.
What are Platelets?
Platelets, also called thrombocytes, are small blood cells that help blood to clot. When a blood vessel gets damaged, platelets gather at the damaged site and make a plug (clot). Clotting helps slow down and stop bleeding and helps wounds heal .
Like other blood cells, platelets are made in the bone marrow. They survive in the circulation for about 8-10 days which is why the bone marrow needs to continually make new ones, to replace old, used ones, or those lost through bleeding [1, 2].
Apart from wound healing, platelets are also involved in immune system defense and inflammation [3, 4].
When there are too many or too few platelets, you can experience problems with blood clots or wound healing .
A platelet count can be used to:
- Help diagnose various issues such as bleeding or clotting disorders or bone marrow disease
- Monitor a known underlying health condition
- Monitor a treatment with drugs known to affect platelets
Platelet count normally ranges from 150 – 450 thousand cells/uL (thousand cells per microliter) . This range may vary slightly depending on the laboratory that does the testing.
Low Platelet Count (Thrombocytopenia)
Low platelet count is also known as thrombocytopenia. When there are not enough platelets, the blood doesn’t clot well, which can cause excessive bleeding and prevent wounds from healing properly. Extremely low levels can be life-threatening .
Your doctor will interpret this test, taking into account your medical history and other test results. A result that is slightly low may not be of medical significance, as this test often varies from day to day and from person to person.
Platelets can be low for two main reasons: either when there are issues with making platelets, or when they are destroyed faster than normal. Although some people may have an inherited condition, it is most often caused either by drugs or other underlying health disorders .
Symptoms associated with a low platelet count include [6, 7]:
- Excessive bleeding from wounds or during a menstrual cycle
- Bruising from unknown causes
Causes listed below are commonly associated with a low platelet count. Work with your doctor or another health care professional to get an accurate diagnosis.
Bacterial, viral, and parasite infections can decrease your platelet count. Examples include Helicobacter pylori infection, malaria, dengue, hepatitis, and HIV [8, 9, 10, 11].
2) Nutrient Deficiencies
Bone marrow needs essential nutrients to make blood cells, including platelets. Various nutrient deficiencies can decrease your platelet count. They include:
Excessive alcohol consumption can have toxic effects on platelet function and production. Studies suggest that in people who abuse alcohol, abstaining from alcohol for 2 – 5 days usually leads to a rise in platelet count .
4) High Altitude
Platelet count decreases when people spend time at high altitudes [16, 17].
In one study with 40 healthy men, a consistent decline in platelet number was observed during a 13-month stay at high altitude (4100 m-4500 m). Platelet counts decreased by 12% after a 3 -month stay at high altitude and by 31% after a 13-month stay in comparison to sea level counts .
5) Autoimmune Disorders
Autoimmune disorders can impair bone marrow function, decrease platelet production, or increase the destruction of platelets [18, 19, 20].
Immune thrombocytopenia, or idiopathic thrombocytopenic purpura (ITP), occurs when the immune system mistakenly attacks platelets and destroys them [19, 7].
In an observational study of 230 people, lupus was associated with a low platelet count .
6) Liver and Spleen Disease
Liver and spleen disease often decrease platelets [21, 22, 23, 24].
Low platelet count can be found in up to 70% of people with liver cirrhosis. That’s mainly because the liver is a big producer of thrombopoietin, a hormone that stimulates platelet production (much like erythropoietin stimulates the production of red blood cells). When the liver is diseased or damaged, less thrombopoietin can be produced and platelet production diminishes [21, 24].
Similarly, when the spleen is enlarged, an increased amount of both thrombopoietin and platelets gets destroyed in the spleen, resulting in a low platelet count [24, 23].
7) Toxin Exposure
Exposure to toxic chemicals, such as benzene, toluene, or similar compounds found in pesticides, can decrease your platelet count [25, 26, 27, 28].
8) Bone Marrow Diseases and Disorders
Bone marrow failure, also called aplastic anemia, is when the bone marrow stops producing new blood cells, including platelets . Aplastic anemia is caused by bone marrow damage that can be inborn, autoimmune or can occur after exposure to radiation, chemotherapy, toxic chemicals, some drugs or infection.
In addition, various cancers, such as ones that spread to the bone marrow like leukemia and lymphoma, can cause low platelet levels. The severity of thrombocytopenia (low platelets) will depend on the type, stage, and malignancy of the cancer [30, 31, 32, 33].
9) Chemo or Radiation Therapy
Radiation therapy and chemotherapy for cancer can decrease platelet counts [34, 35].
Many drugs, other than chemotherapeutics, can also decrease platelet counts, including [36, 37]:
- Medication that reduces or prevents blood clotting (anti-coagulants), such as heparin [38, 39]
- Aspirin and ibuprofen [40, 41]
- Some antibiotics 
- Quinine, a medication used to treat malaria and babesiosis 
11) Rare Genetic Disorders
Sometimes, a low platelet count may be due to rare genetic disorders (e.g. Wiskott–Aldrich syndrome) [44, 45, 46]
If your platelet count is low, the most important thing is to work with your doctor to find out what’s causing your low platelet count and to treat any underlying conditions!
Other than that, you can check your nutrient levels (iron, vitamin B12, folate) and make sure your diet is well balanced and contains the right amount of these nutrients [12, 14, 13].
Reducing alcohol intake can prevent your platelet levels from dropping too low .
Finally, some drugs can decrease your platelet levels. If you are taking such drugs, speak with your doctor to discuss possible alternatives .
High Platelet Count (Thrombocytosis)
High platelet count is also known as thrombocytosis. There are 3 main types :
- Spurious or “false” thrombocytosis is very rare and occurs when blood tests falsely recognize bacteria as platelets
- Reactive thrombocytosis can be caused by infections and inflammatory disorders
- Clonal thrombocytosis occurs when there is abnormal platelet production
Your doctor will interpret this test, taking into account your medical history and other test results. A result that is slightly high may not be of medical significance, as this test often varies from day to day and from person to person.
Normally, a high platelet count doesn’t cause any symptoms. However, it can sometimes cause blood clots. These blood clots can, in turn, cause :
- Discomfort in the neck, jaw, or arms
If your platelets are high, they may falsely elevate blood potassium and phosphorus levels .
Causes listed below are commonly associated with a high platelet count. Work with your doctor or another health care professional to get an accurate diagnosis.
Inflammatory disorders, such as rheumatoid arthritis or inflammatory bowel disease (IBD), are the most common causes of increased platelet counts [50, 51, 52].
Some infectious diseases can increase your platelet count. They are most often soft tissue (Staphylococcus, Streptococcus), lung (tuberculosis), and stomach/gut infections [53, 54].
3) Exercise/physical exhaustion
Exercise and physical exhaustion can temporarily increase your platelet count [55, 56].
4) Recovery from Blood Loss
Recovery from blood loss after surgery or injury can increase platelet counts [57, 58].
5) Iron-deficiency Anemia
High platelet count is often found in iron-deficiency anemia. In an observational study, 31% of the studied 140 people with iron-deficiency anemia had elevated platelet counts .
6) Alcohol Withdrawal After Heavy Drinking
Drinking alcohol initially decreases your platelet count. However, when the alcohol is gone from your system the body overcompensates leading to a rebound effect and thrombocytosis (high platelet count) [60, 61, 62].
This rebound effect is associated with heavy alcohol drinking and is not observed with moderate red wine consumption, for example .
7) Estrogen Therapy and Birth Control Pills
Birth control pills (oral contraceptives) and estrogen therapy can both increase platelet count [64, 65].
8) Spleen Removal
Having your spleen removed (splenectomy) can significantly increase your platelet count [48, 66].
9) Primary Thrombocythemia
Primary thrombocythemia is a rare bone marrow disorder in which the bone marrow produces too many platelets [67, 68]. It’s not clear what causes this disorder, but it’s likely partially due to genetics.
Various types of cancer can increase platelet counts (e.g. lymphoma, breast, lung, ovarian and stomach/gut cancer) [69, 70, 71, 72, 73, 74].
If your platelet count is high, the most important thing is to work with your doctor to find out what’s causing your high platelet count and to treat any underlying conditions!
Avoid overindulging in alcohol. As mentioned above, heavy alcohol drinking causes fluctuations in your platelet count. First platelets will decrease, then after withdrawal, they will increase above the normal range [60, 61, 62].
In addition, you can check your iron levels. Make sure your diet is well balanced and contains all the necessary nutrients in adequate amounts .