Vascular problems account for the majority of cases and can be caused by diseases such as high blood pressure, type 2 diabetes, high cholesterol, and cardiovascular disease, according to the American Urological Association (AUA).

More men experience impotence as they age, according to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).

Orgasm and ejaculation are separate physical processes.

But emotional and psychological issues usually are secondary factors that occur after impotence is experienced, the NIDDK says.

The medications usually prescribed are known as phosphodiesterase-5 inhibitors (PDE-5), according to the AUA.

Oral testosterone may help. Some drugs can be injected or inflatable pumps can be implanted.