Persons with sickle cell disease (SCD) are prone to crises occurring when they experience abrupt changes in temperature or have a fever, are dehydrated, or hypoxic (including entering high altitudes where oxygen is decreased). Physical exertion, pregnancy, and psychological stresses can also precipitate sickle cell crises.
Prognosis in SCD is related to the number of sickle cell crisis episodes. Persons who experience more than three episodes of crisis requiring treatment in a single year, have a poor prognosis.
The average age of survival for women with sickle cell disease (Hb SS) is 48 years, while for men the average age of survival is 42 years.