What are the causes of impotence?

There are numerous different causes of impotence. In young, healthy men, difficulty gaining or sustaining an erection is most often associated with psychological factors, but there is sometimes a physical cause. Sometimes it's a mixture of the two.

• Psychological: Performance anxiety, relationship problems, depression, stress, fatigue, loss of interest in sex.
• Physical: Diabetes, vascular disease, spinal cord injury, surgery, some prescription medicines, smoking, drinking, drug abuse, hormonal imbalance, epilepsy, multiple sclerosis.