An erection is an involuntary reaction in response to sexual, psychological, sensory and nerve stimulation. This stimulation causes a rapid increase in the amount of blood flowing into the penis. An erection occurs when blood becomes trapped and held i the two cylindrical chambers that make up most of the shaft of the penis. As the chambers rapidly fill with blood, they expand and the penis becomes firm and elongated, resulting in a successful erection. Impotence or sexual dysfunction refers to the inability to have or maintain a satisfactory erection, or the inability to achieve successful sexual intercourse.
Impotence can be total or partial and it can affect men of different age groups.
Approximately 20 to 30 million men in the United States, or 1 in every 10 men, are affected by this condition. Impotence is not an inevitable consequence of aging. The age-old problem of impotence has been recorded in writing of the ancient Chinese, Egyptians, and Greeks. Some ancient cultures even described recipes for erotic potions to help cure sexual problems. The causes and cures have always been abundant.