A man who cannot develop or sustain an erection to perform satisfactory sexual intercourse is termed 'impotent'. Unfortunately, this term has serious social consequences and should be used with caution and after due consideration of the complex process of male sexual function.

Besides the inability to sustain erection other factors like loss of desire or libido, inability to ejaculate at the right time, difficulty in achieving orgasms, all coexist in some individuals and contribute to the patient's loss of confidence and inadequacy. Erectile dysfunction occurs in 5% of all males above 40 years of age and this percentage increases with advancing age.

The penis consists of large open spaces confined within a tight capsule. These spaces contain blood. Erection is brought about by a complex method of influences that travel from the brain, originating in the hormonal system and acting through the peripheral nerves. These result in the filling up of the spaces with blood, and this blood cannot flow out. This engorgement of the spaces with blood makes the penis rigid. Once the influences are withdrawn, as after orgasm and ejaculation, blood drains out from the spaces making the penis flaccid.

The causes are most often psychological and may include performance anxiety, guilt, depression or a fear of failure. It is important to rule out the physical causes. Besides progressing age, other factors include diseases like diabetes, high blood pressure and obesity. Smoking, excessive intake of alcohol and lack of physical activity can aggravate the problem. Persons with depression, anxiety, chronic stress and difficult relationships have a higher chance of having erectile dysfunction.

Other diseases that predispose to the condition include decreased thyroid function and kidney failure. Some drugs like anti-depressants, tranquillisers and medicines for high blood pressure may also lead to impotence.

The doctor will take a detailed medical history to determine whether impotence is due to an physical illness or due to psychological problems. Similarly, a detailed examination of the body including examination of the sexual organs will be done. Blood tests may be done to exclude diabetes or high cholesterol. Specialised tests may be done in specific instances to locate a problem in the structure and function of the penis.

rectile dysfunction due to a psychological problem is treated with much care. Usually the problem is due to performance anxiety, guilt, depression or a fear of failure. The patient is explained that this only worsens the problem. Sex education helps correct misinformation and ignorance about normal sexual practice. In married couples, discussing the problem with both partners may help the doctor to arrive at the root cause of anxiety or performance failure. These treatment sessions are usually time-consuming and slow.

The psychological treatment can be supplemented with the help of medicines that stimulate erection. These can be taken orally like sildenafil (viagra) or others that can be injected into the penis like papaverine or alprostadil, a synthetic prostaglandin. For men with low levels of male sex hormone, testosterone, this hormone may need to be supplemented. In some cases that do not satisfactorily respond to medicines, erections can be achieved with the help of appliances like vacuum devices or the insertion of implants into the penis by an operation.