Pathology of erection.

Erectile dysfunction (ED) is defined as the inability to achieve and maintain a penile erection which is adequate for satisfactory sexual intercourse. It is a significant male health problem affecting approximately 150 million men worldwide. This value is expected to more than double by the year 2025. The incidence of ED increases sharply with age since it is a common cross-cultural denominator, affecting 19 to 64% of men aged 40 to 80 years, both in developing and industrialized countries. Epidemiological studies may underestimate the true dimensions of the problem because of the embarrassment or stigma that is associated with ED. Men with ED may experience diminished self-image and self-esteem, anxiety and fears of rejection, and even depression as psychogenic factors. Pathologic conditions which are commonly encountered in the ageing male (diabetes, hypertension, atherosclerosis, cardiovascular disease, etc) as well as chronic diseases (arthritis, renal and hepatic failure, pulmonary disease) represent a frequent cause of organic ED and are often treated with medications that can interfere with sexual function at central and/or peripheral level. In addition, incorrect lifestyle--i.e. obesity, cigarette smoking, alcohol or drug abuse--may all contribute to the onset of ED. Finally, trauma or surgery affecting either the nervous system or interfering with the blood supply to the penis are associated with increased incidence of ED.