Dear Brenda, Erectile dysfunction has many causes. In order to have an erection, one needs to have a penis which is normal , i.e. no scar tissue in the erectile tissue which produces erection. These may include certain medications, psychological issues, etc. Priapism is a prolonged painful erection the does not result from sexual desire and does not subside despite orgasm. Normally, blood enters the erectile tissues of the penis and forms an erection which subsides with an orgasm.
Priapism lets the blood into the penis but won t let it out with an orgasm.
This is refereed to as high flow and low flow state priapism, respectfully. High flow state is usually associated with trauma. Low flow state is more common and is associated with sickle cell disease, and various medications. The treatment of priapism is to remove blood from the corporeal bodies. Sometimes medication in the form of injection can be used to achieve this, some times an incision needs to be used.