Hypertension in sickle cell disease.

We report a young male with sickle cell trait who developed severe hypertension and splenic infarction soon after travel to a high altitude. Hypertension persisted for three days after a diagnostic laparotomy. His blood pressure then continued to be normal over the next one and a half years. Red cell sludging in the small vessels of the kidney possibly activated the renin angiotensin system.