Erection of the penis is a sequential event and any disruption in this sequence can cause erectile dysfunction (ED) or impotence. The sequence includes nerve impulse in the brain, spinal column, the area around the penis, and response in muscles, fibrous tissues, veins, and arteries in and around corpora cavernosa. Damage to nerves, arteries, smooth muscles, fibrous tissues often as a result of the disease is the most common cause of erectile dysfunction (ED) or impotence.