Some men, however, experience chronic, complete erectile dysfunction (impotence), and others, partial or brief erections. Frequent erectile dysfunction can cause emotional and relationship problems, and often leads to diminished self-esteem. Erectile dysfunction has many causes, most of which are treatable, and is not an inevitable consequence of aging.

Incidence and Prevalence
The term "erectile dysfunction" can mean the inability to achieve erection, an inconsistent ability to do so, or the ability to achieve only brief erections. These various definitions make estimating the incidence of erectile dysfunction difficult. According to the National Institutes of Health in 2002, an estimated 15 million to 30 million men in the United States experience chronic erectile dysfunction.

Anatomy of the Penis
The internal structure of the penis consists of two cylinder-shaped vascular tissue bodies (corpora cavernosa) that run throughout the penis; the urethra (tube for expelling urine and ejaculate); erectile tissue surrounding the urethra; two main arteries; and several veins and nerves. The longest part of the penis is the shaft, at the end of which is the head, or glans penis. The opening at the tip of the glans, which allows for urination and ejaculation, is the meatus.

Physiology of Erection
The physiological process of erection begins in the brain and involves the nervous and vascular systems. Neurotransmitters in the brain (e.g., epinephrine, acetylcholine, nitric oxide) are some of the chemicals that initiate it. Physical or psychological stimulation (arousal) causes nerves to send messages to the vascular system, which results in significant blood flow to the penis. Two arteries in the penis supply blood to erectile tissue and the corpora cavernosa, which become engorged and expand as a result of increased blood flow and pressure.

Because blood must stay in the penis to maintain rigidity, erectile tissue is enclosed by fibrous elastic sheathes (tunicae) that cinch to prevent blood from leaving the penis during erection. When stimulation ends, or following ejaculation, pressure in the penis decreases, blood is released, and the penis resumes its normal shape.

Did You Know?

• That by the age of 27, 97% of men can’t have erections 1/5 as much as when they were 20.
  
  
• That 30 million men in the USA alone suffer from Erectile Dysfunction (Impotence). This number is even higher for woman with (FSAD) female sexual arousal disorder.
  
  
• That by the time he’s 50, the average man will have lost .5” (half an inch) in length from his penis. The main reason for this is blood restriction to the main cylinders of the penis.
  
  
• That nearly 88.7% of men would try to improve their erection quality if they had an easy solution which avoided the hassles of visiting their health care provider.
  
  
• That the average man  ejaculates within 2 to 2½ minutes of insertion into the female. Improper blood flow causes lack of stamina.
  
  
• That 98% of men have a much weaker, smaller more underdeveloped penis compared to what they could possess.
  
  
• That in a poll conducted by DurexTM Condoms, 67% of women said they were unhappy with their lover’s erection quality.