In order to feel like having sex you need a certain level of health and a sense of wellbeing. Physical causes that possibly influence the desire to make love for men are:

Diseases that disturb the hormonal balance.

Diseases with chronic pain, for example chronic rheumatoid arthritis.

Diseases that involve fatigue, serious anemia or the chronic fatigue syndrome.

Diseases that reduce the general well being: cancer, aids.

Diseases with a depressive tendency.

Consequences of infertility and treatments for this: sex feels like an obligation. Various medications: see also other questions.

Testosterone is a hormone that influences, among other things, the desire to make love in men. An extremely low testosterone level in men can be the direct cause of being less interested in making love. This shortage of testosterone may have several causes. Congenital disorders in the production of testosterone can cause the development of puberty to fail, as well as sexual interest. Nowadays these cases are diagnosed in time and shouldn't cause any problems in the development. Congenital anomalies of the testicles can also cause a low testosterone level. If these anomalies have existed since birth, the reduced feelings or no interest at all in sex should also have existed since birth. Cancer treatments can cause damage to the testicles; through medication and radiation therapy a loss of function can occur.

Prolactin, another hormone, has a restraining effect on the desire for sex when present at very high levels.

High doses of estrogenic hormones for example in the treatment of prostate cancer always lead to a reduction of sexual interest.

Chronic diseases e.g diseases of the kidneys, heart and vascular diseases, liver cirrhosis and alcoholism, heroin and cocaine addiction can lead to a reduced interest in making love.