Deficiencies of testosterone or thyroid hormones. Elevated level of prolactin, another hormone involved in sexual function. Hardening of the arteries. Physical deformities of the penis. Spinal cord injuries.
Impotence is often the first important sign of a hypothalamic-pituitary abnormality.
Damage of the vital nerves that control erection and ejaculation. Controlling weight may lower blood pressure and make high blood pressure medicine unnecessary, or decrease the amount to the point that impotence is no longer a problem. It must be added that excessive weight loss or fad diets can also be a cause of impotence. The first step in correcting impotence is to identify the cause. If it is psychological, counseling is the right approach.