Q: Increase platelets in which diseases A: Increased platelet count thrombocytosis occurs in: Primary causes: myeloproliferative neoplasms - Essential thrombocythemia - Polycythemia vera - Chronic myeloid leukemia CML - Primary myelofibrosis agnogenic myeloid metaplasia Secondary or reactive causes - Iron-deficiency anemia - Acute blood loss or hemorrhage - Chronic infection or inflammation, such as tuberculosis, rheumatoid arthritis, inflammatory bowel disease - Solid cancers/malignancies - After splenectomy - Rebound after recovery from bone marrow suppression, for example after chemotherapy Reactive thrombocytosis accounts for most cases. Henry's Clinical Diagnosis and Management by Laboratory Methods, p. 908.