Priapism

Priapism is a condition in which a penis remains erect for hours in the absence of stimulation or after stimulation has ended. It has three recognized types: ischemic, nonischemic, and recurrent ischemic, with ischemic cases making up the large majority. Ischemic priapism typically causes pain with hardness throughout most of the penis while the glans remains soft, whereas nonischemic priapism is painless and produces only partial hardening; sickle cell disease is the most frequent cause of the ischemic form, though certain medications and substances can also trigger the condition.