Thomas, AkeshAlex, RobertDon, Babu Chemplavil2020-01-022020-01-022018-05Thomas Akesh, Alex Robert, Don Babu Chemplavil. Unusual Presentation Of Jak2-Negative Polycythemia. Indian Journal of Case Reports. 2018 May; 4(3): 176-1782454-129X2454-1303http://imsear.searo.who.int/handle/123456789/190546Polycythemia vera is a relatively rare disease occurring in 0.02–2.8 per million population. Globally, about 95% of PV is due to JAK2V617F mutation in the chromosome 9p. The remaining 5% were found to have a wide range of mutations including JAK2 exon12 mutation and calreticulin (CALR) mutation. In India, the incidence of JAK2-negative polycythemia is relatively high, reaching up to 18%. Polycythemia usually presents as symptoms secondary to hyperviscosity or as symptoms secondary to increased histamine release by the cells. Herein, we describe a 46-year-old Indian male presented with a headache and found to be in hypertensive urgency, which was later found to be secondary to JAK2-negative polycythemiaJournal ArticleIndiaMBBS, Primary Care Medical Officer, CSI Holdsworth Memorial Hospital, Mangalore, Karnataka, India|MBBS, Resident Medical Officer, CSI Holdsworth Memorial Hospital, Mangalore, Karnataka, India3MBBS, Department of Internal Medicine, CSI Holdsworth Memorial Hospital, Mangalore, Karnataka, India