8 Things That Elevate Your Platelet Count

Chronic myleoproliferative disorders (a disorder where the bone marrow makes too many blood cells) can cause thrombocytosis. These include polycythemia vera, essential thrombocythemia (ET), and primary myelofibrosis.

In ET, for example, the bone marrow makes too many megakaryocytes, the cells that make platelets, resulting in thrombocytosis. With these conditions, the excessive numbers of platelets cause the blood to be thick and flow more slowly which may result in blood clots. Treatment is aimed at reducing the platelet count to reduce this risk.

In both children and adults, infections are the most common cause of an elevated platelet count. This elevation can be extreme, with platelet counts greater than one million cells per microliter.

The majority of people who experience this are asymptomatic but a small group of patients with other risk factors may develop blood clots. Platelet counts generally return to normal after resolution of the infection, but this may take several weeks. In some patients, thrombocytosis may be a rebound effect after having thrombocytopenia (low platelets) during initial infection.

Although a low hemoglobin and small red blood cells are the typical laboratory values associated with iron deficiency anemia, elevation of the platelet count is not uncommon. At this time, it is unknown what exactly causes this thrombocytosis. In general, it is well tolerated and resolves with appropriate iron supplementation treatment.​

A certain amount of platelets are housed in our spleen at any given time. If the spleen is removed surgically (splenectomy) or stops functioning properly (functional asplenia) as in sickle cell disease, thrombocytosis results. This thrombocytosis is usually mild to moderate and well tolerated.

Immediately after splenectomy, the thrombocytosis may be severe and may trigger the formation of a blood clot. This post-splenectomy complication occurs in about 5 percent of patients. In general, the risk is greatest in the month after splenectomy.

Conditions with inflammation like rheumatologic disorders, inflammatory bowel disease, and vasculitides can have thrombocytosis. The elevated platelet count occurs in response to cytokines (small proteins released from cells that signal other cells to do something). In particular, the cytokines interleukin-6 and thrombopoietin stimulate platelet production.

Mixed cryoglobulinemia can cause a false elevation in the platelet count. In this condition, cryoglobulins (proteins) in the blood stick together when exposed to cold temperatures (like the hands and feet). These particles may be falsely counted as platelets by the machine performing the complete blood count. This condition is associated with hepatitis C infection, systemic lupus erythematosus, and rheumatoid arthritis.

If the hemolytic anemia (anemia secondary to red blood cell fragmentation) results in the formation of very small red blood cells, these red blood cells may be inaccurately counted as platelets by the machine that performs the complete blood count. This can be diagnosed by reviewing a peripheral blood smear (a microscope slide of blood). A visual count of the platelets will be lower with many small red blood cells seen.

Thrombocytosis can be a secondary effect of some malignancies (cancer). This is known as paraneoplastic thrombocytosis. This is more common in solid tumors like lung cancer, hepatocellular (liver) carcinoma, ovarian cancer, and colorectal cancer. Elevated platelet count can also be seen in chronic myelogenous leukemia (CML).