Table of ContentsView AllTable of ContentsWhat Is a High Count?DiagnosisWhen It May Be ConcerningLess Concerning CausesTreatmentOutlookWhen to See a Provider
Table of ContentsView All
View All
Table of Contents
What Is a High Count?
Diagnosis
When It May Be Concerning
Less Concerning Causes
Treatment
Outlook
When to See a Provider
Thrombocytosis, or a high platelet count, is diagnosed when platelet levels are greater than 450,000 platelets per microliter of blood.It’s not always obvious when to worry about a high platelet count. Many times, a highplatelet countisn’t serious and may not cause symptoms. However, having a high platelet count can lead to blood clotting problems and, in some cases, may be associated with serious conditions like cancer.
A high platelet count may be found during routine blood work and more tests may be done to diagnose any associated conditions. Treatment will vary depending on the underlying cause, and in some cases, may not be necessary.
What Is a High Platelet Count?
A high platelet count is more than 450,000 platelets per microliter of blood.This condition is known asthrombocytosis.
There are two types:
Normal Platelet CountA normal platelet count is about 150,000 to 450,000 platelets per microliter of blood.Platelets, also called thrombocytes, are the cells in the blood that help blood clot.
Normal Platelet Count
A normal platelet count is about 150,000 to 450,000 platelets per microliter of blood.Platelets, also called thrombocytes, are the cells in the blood that help blood clot.
What Do Healthcare Providers Look For?
When determining whether or not a high platelet count is something to worry about, healthcare providers may look for symptoms like bruising, bleeding, and signs of infection or another underlying condition.
It is likely that blood tests or imaging will be done. These tests may include:
When a High Platelet Count May Be Concerning
A high platelet count may be worrisome if:
Blood Clots
In general, blood clots tend to be linked to primary thrombocytosis. However, they can also occur with secondary thrombocytosis.
Certain individuals are more at risk of developing clots, including those who:
Blood clots may form in any blood vessel and prevent blood from flowing properly. Most commonly, they form in the blood vessels in the arms and legs, or in the brain. This decreased blood flow can cause symptoms including:
If you have a high platelet count and are worried about the risk of developing blood clots, talk to your healthcare provider.
High Platelet Count in Pregnancy
During pregnancy, sometimes platelet levels can become too low or too high. In some cases this is due to a problem that existed prior to pregnancy; in others, it comes on during pregnancy.
A very high platelet count can cause blood clots that can block blood flow to the embryo or fetus, while low platelet counts can cause bleeding.
Complications associated with high platelet levels include:
Cancer
Cancer is linked to both primary and secondary thrombocytosis. Cancer can cause secondary thrombocytosis, which may be one of the first signs of certain types of cancer. On rare occasions, primary thrombocytosis can turn into certain types of cancer.
A high platelet count is associated with certain kinds of cancer, including:
The mostcommon cancersthat cause a high platelet count include gastrointestinal cancer, lymphoma, ovarian cancer, lung cancer, and breast cancer.
Less Concerning Causes of High Platelet Count
A high platelet count may be less worrisome if it is associated with:
While these conditions and circumstances tend to result in a high platelet count returning to normal, if these aren’t treated, monitored, or managed appropriately, they can lead to more concerning risks.
How Do You Treat a High Platelet Count?
Treating a high platelet count starts with finding the underlying cause. There are two types o
In some cases, if there are no symptoms, no treatment may be required.
Treatment for essential thrombocythemiamay include certain medications that slow down the production of platelets. In secondary thrombocytosis, treating the underlying condition, like an infection, may be all that is needed to decrease high platelet levels.
What Is the Outlook for Those With High Platelet Counts?
However, having a high platelet count can be associated with cancer. A 2017 study compared 40,000 people with high platelets to 10,000 people with normal platelets and found that a high platelet count is associated with cancer risk.
Specifically, males with high platelet counts were found to have an 11.6% incidence of cancer, compared to 4.1% for those without. In females, the incidence was 6.2% for those with high platelet counts, and 2.2% for those without.
For people who still had high platelet counts six months later, the incidence went up to 18.1% for males and 10.1% for females. Lung and colorectal cancer were the two most commonly diagnosed cancers in people with thrombocytosis.
When to See a Healthcare Provider
You should see a healthcare provider about high platelets if you:
Seek emergency treatment if you have any of these symptoms:
Summary
Having a high platelet count, or thrombocytosis, doesn’t always indicate something serious is going on. Many times, it is linked to a temporary condition or circumstance, such as an infection or recent surgery. However, high platelet levels can be associated with more serious conditions, such as cancer.
Treatment for elevated platelet levels will vary depending on the underlying cause. In some cases, no treatment may be required.
A Word From VerywellPlatelets are cells found in our bone marrow and peripheral blood that are instrumental in clotting. While the upper limit of normal for the platelet count is 450,000 platelets/ul in peripheral blood, a number slightly above this is not a cause for concern. Platelets are elevated (thrombocytosis) for primary and secondary reasons. Treatment, if necessary, involves treating the underlying condition.—STEFFINI STALOS, DO, MEDICAL EXPERT BOARD
A Word From Verywell
Platelets are cells found in our bone marrow and peripheral blood that are instrumental in clotting. While the upper limit of normal for the platelet count is 450,000 platelets/ul in peripheral blood, a number slightly above this is not a cause for concern. Platelets are elevated (thrombocytosis) for primary and secondary reasons. Treatment, if necessary, involves treating the underlying condition.—STEFFINI STALOS, DO, MEDICAL EXPERT BOARD
Platelets are cells found in our bone marrow and peripheral blood that are instrumental in clotting. While the upper limit of normal for the platelet count is 450,000 platelets/ul in peripheral blood, a number slightly above this is not a cause for concern. Platelets are elevated (thrombocytosis) for primary and secondary reasons. Treatment, if necessary, involves treating the underlying condition.
—STEFFINI STALOS, DO, MEDICAL EXPERT BOARD
17 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Johns Hopkins Medicine.What are platelets and why are they important?NIH. National Heart, Lung, and Blood Institute.Platelet disorders: diagnosis.MedlinePlus.Essential thrombocythemia.National Heart, Lung, and Blood Institute.Thrombocythemia and thrombocytosis.Watson J, Jones HE, Banks J, Whiting P, Salisbury C, Hamilton W.Use of multiple inflammatory marker tests in primary care: using clinical practice research datalink to evaluate accuracy.Br J Gen Pract. 2019;69(684):e462-e469. doi:10.3399/bjgp19X704309Centers for Disease Control and Prevention.Venous thromboembolism (Blood clots).İskender D, Yılmaz-Ergani S, Aksoy M, et al.High rate of obstetric complications in patients with essential thrombocythemia.Cureus. 2021;13(12):e20449. doi:10.7759/cureus.20449İskender D, Yılmaz-Ergani S, Aksoy M, et al.High rate of obstetric complications in patients With essential thrombocythemia.Cureus. 2021;13(12):e20449. doi:10.7759/cureus.20449Leukemia and Lymphoma Society.Essential thrombocythemia.Heber S, Volf I.Effects of physical (in)activity on platelet function.Biomed Res Int. 2015;2015:165078. doi:10.1155/2015/165078Koudouovoh-Tripp P, Hüfner K, Egeter J, et al.Stress enhances proinflammatory platelet activity: the impact of acute and chronic mental stress.J Neuroimmune Pharmacol500–512 (2021). doi:10.1007/s11481-020-09945-4Jeon, GW.Pathophysiology, classification, and complications of common asymptomatic thrombocytosis in newborn infants.Clin Exp Pediatr. 2022;65(4):182-187. doi:10.3345/cep.2021.00864Kucine N, Chastain KM, Mahler MB, Bussel JB.Primary thrombocytosis in children.Haematologica. 2014 Apr;99(4):620-8. doi:10.3324/haematol.2013.092684Zvizdic Z, Kovacevic A, Milisic E, Jonuzi A, Vranic S.Clinical course and short-term outcome of postsplenectomy reactive thrombocytosis in children without myeloproliferative disorders: A single institutional experience from a developing country.PLoS One. 2020;15(8):e0237016. doi:10.1371/journal.pone.0237016Vo QT, Thompson DF.A review and assessment of drug-induced thrombocytosis.Annals of Pharmacotherapy. 2019;53(5):523-536. doi:10.1177/1060028018819450Bailey SE, Ukoumunne OC, Shephard EA, Hamilton W.Clinical relevance of thrombocytosis in primary care: A prospective cohort study of cancer incidence using English electronic medical records and cancer registry data.Br J Gen Pract. 2017;67(659):e405-e413. doi:10.3399/bjgp17X691109NIH. National Heart, Lung, and Blood Institute.Platelet disorders: symptoms.
17 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Johns Hopkins Medicine.What are platelets and why are they important?NIH. National Heart, Lung, and Blood Institute.Platelet disorders: diagnosis.MedlinePlus.Essential thrombocythemia.National Heart, Lung, and Blood Institute.Thrombocythemia and thrombocytosis.Watson J, Jones HE, Banks J, Whiting P, Salisbury C, Hamilton W.Use of multiple inflammatory marker tests in primary care: using clinical practice research datalink to evaluate accuracy.Br J Gen Pract. 2019;69(684):e462-e469. doi:10.3399/bjgp19X704309Centers for Disease Control and Prevention.Venous thromboembolism (Blood clots).İskender D, Yılmaz-Ergani S, Aksoy M, et al.High rate of obstetric complications in patients with essential thrombocythemia.Cureus. 2021;13(12):e20449. doi:10.7759/cureus.20449İskender D, Yılmaz-Ergani S, Aksoy M, et al.High rate of obstetric complications in patients With essential thrombocythemia.Cureus. 2021;13(12):e20449. doi:10.7759/cureus.20449Leukemia and Lymphoma Society.Essential thrombocythemia.Heber S, Volf I.Effects of physical (in)activity on platelet function.Biomed Res Int. 2015;2015:165078. doi:10.1155/2015/165078Koudouovoh-Tripp P, Hüfner K, Egeter J, et al.Stress enhances proinflammatory platelet activity: the impact of acute and chronic mental stress.J Neuroimmune Pharmacol500–512 (2021). doi:10.1007/s11481-020-09945-4Jeon, GW.Pathophysiology, classification, and complications of common asymptomatic thrombocytosis in newborn infants.Clin Exp Pediatr. 2022;65(4):182-187. doi:10.3345/cep.2021.00864Kucine N, Chastain KM, Mahler MB, Bussel JB.Primary thrombocytosis in children.Haematologica. 2014 Apr;99(4):620-8. doi:10.3324/haematol.2013.092684Zvizdic Z, Kovacevic A, Milisic E, Jonuzi A, Vranic S.Clinical course and short-term outcome of postsplenectomy reactive thrombocytosis in children without myeloproliferative disorders: A single institutional experience from a developing country.PLoS One. 2020;15(8):e0237016. doi:10.1371/journal.pone.0237016Vo QT, Thompson DF.A review and assessment of drug-induced thrombocytosis.Annals of Pharmacotherapy. 2019;53(5):523-536. doi:10.1177/1060028018819450Bailey SE, Ukoumunne OC, Shephard EA, Hamilton W.Clinical relevance of thrombocytosis in primary care: A prospective cohort study of cancer incidence using English electronic medical records and cancer registry data.Br J Gen Pract. 2017;67(659):e405-e413. doi:10.3399/bjgp17X691109NIH. National Heart, Lung, and Blood Institute.Platelet disorders: symptoms.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Johns Hopkins Medicine.What are platelets and why are they important?NIH. National Heart, Lung, and Blood Institute.Platelet disorders: diagnosis.MedlinePlus.Essential thrombocythemia.National Heart, Lung, and Blood Institute.Thrombocythemia and thrombocytosis.Watson J, Jones HE, Banks J, Whiting P, Salisbury C, Hamilton W.Use of multiple inflammatory marker tests in primary care: using clinical practice research datalink to evaluate accuracy.Br J Gen Pract. 2019;69(684):e462-e469. doi:10.3399/bjgp19X704309Centers for Disease Control and Prevention.Venous thromboembolism (Blood clots).İskender D, Yılmaz-Ergani S, Aksoy M, et al.High rate of obstetric complications in patients with essential thrombocythemia.Cureus. 2021;13(12):e20449. doi:10.7759/cureus.20449İskender D, Yılmaz-Ergani S, Aksoy M, et al.High rate of obstetric complications in patients With essential thrombocythemia.Cureus. 2021;13(12):e20449. doi:10.7759/cureus.20449Leukemia and Lymphoma Society.Essential thrombocythemia.Heber S, Volf I.Effects of physical (in)activity on platelet function.Biomed Res Int. 2015;2015:165078. doi:10.1155/2015/165078Koudouovoh-Tripp P, Hüfner K, Egeter J, et al.Stress enhances proinflammatory platelet activity: the impact of acute and chronic mental stress.J Neuroimmune Pharmacol500–512 (2021). doi:10.1007/s11481-020-09945-4Jeon, GW.Pathophysiology, classification, and complications of common asymptomatic thrombocytosis in newborn infants.Clin Exp Pediatr. 2022;65(4):182-187. doi:10.3345/cep.2021.00864Kucine N, Chastain KM, Mahler MB, Bussel JB.Primary thrombocytosis in children.Haematologica. 2014 Apr;99(4):620-8. doi:10.3324/haematol.2013.092684Zvizdic Z, Kovacevic A, Milisic E, Jonuzi A, Vranic S.Clinical course and short-term outcome of postsplenectomy reactive thrombocytosis in children without myeloproliferative disorders: A single institutional experience from a developing country.PLoS One. 2020;15(8):e0237016. doi:10.1371/journal.pone.0237016Vo QT, Thompson DF.A review and assessment of drug-induced thrombocytosis.Annals of Pharmacotherapy. 2019;53(5):523-536. doi:10.1177/1060028018819450Bailey SE, Ukoumunne OC, Shephard EA, Hamilton W.Clinical relevance of thrombocytosis in primary care: A prospective cohort study of cancer incidence using English electronic medical records and cancer registry data.Br J Gen Pract. 2017;67(659):e405-e413. doi:10.3399/bjgp17X691109NIH. National Heart, Lung, and Blood Institute.Platelet disorders: symptoms.
Johns Hopkins Medicine.What are platelets and why are they important?
NIH. National Heart, Lung, and Blood Institute.Platelet disorders: diagnosis.
MedlinePlus.Essential thrombocythemia.
National Heart, Lung, and Blood Institute.Thrombocythemia and thrombocytosis.
Watson J, Jones HE, Banks J, Whiting P, Salisbury C, Hamilton W.Use of multiple inflammatory marker tests in primary care: using clinical practice research datalink to evaluate accuracy.Br J Gen Pract. 2019;69(684):e462-e469. doi:10.3399/bjgp19X704309
Centers for Disease Control and Prevention.Venous thromboembolism (Blood clots).
İskender D, Yılmaz-Ergani S, Aksoy M, et al.High rate of obstetric complications in patients with essential thrombocythemia.Cureus. 2021;13(12):e20449. doi:10.7759/cureus.20449
İskender D, Yılmaz-Ergani S, Aksoy M, et al.High rate of obstetric complications in patients With essential thrombocythemia.Cureus. 2021;13(12):e20449. doi:10.7759/cureus.20449
Leukemia and Lymphoma Society.Essential thrombocythemia.
Heber S, Volf I.Effects of physical (in)activity on platelet function.Biomed Res Int. 2015;2015:165078. doi:10.1155/2015/165078
Koudouovoh-Tripp P, Hüfner K, Egeter J, et al.Stress enhances proinflammatory platelet activity: the impact of acute and chronic mental stress.J Neuroimmune Pharmacol500–512 (2021). doi:10.1007/s11481-020-09945-4
Jeon, GW.Pathophysiology, classification, and complications of common asymptomatic thrombocytosis in newborn infants.Clin Exp Pediatr. 2022;65(4):182-187. doi:10.3345/cep.2021.00864
Kucine N, Chastain KM, Mahler MB, Bussel JB.Primary thrombocytosis in children.Haematologica. 2014 Apr;99(4):620-8. doi:10.3324/haematol.2013.092684
Zvizdic Z, Kovacevic A, Milisic E, Jonuzi A, Vranic S.Clinical course and short-term outcome of postsplenectomy reactive thrombocytosis in children without myeloproliferative disorders: A single institutional experience from a developing country.PLoS One. 2020;15(8):e0237016. doi:10.1371/journal.pone.0237016
Vo QT, Thompson DF.A review and assessment of drug-induced thrombocytosis.Annals of Pharmacotherapy. 2019;53(5):523-536. doi:10.1177/1060028018819450
Bailey SE, Ukoumunne OC, Shephard EA, Hamilton W.Clinical relevance of thrombocytosis in primary care: A prospective cohort study of cancer incidence using English electronic medical records and cancer registry data.Br J Gen Pract. 2017;67(659):e405-e413. doi:10.3399/bjgp17X691109
NIH. National Heart, Lung, and Blood Institute.Platelet disorders: symptoms.
Meet Our Medical Expert Board
Share Feedback
Was this page helpful?Thanks for your feedback!What is your feedback?OtherHelpfulReport an ErrorSubmit
Was this page helpful?
Thanks for your feedback!
What is your feedback?OtherHelpfulReport an ErrorSubmit
What is your feedback?
