Erectile dysfunction in men can be caused by psychological factors, endocrine diseases, vascular lesions, drugs and many other reasons. 1. Psychological factors: adverse psychological factors may lead to erectile dysfunction. On the one hand, anxiety, irritability, depression and other adverse psychological states can affect the level of hormones in the body, leading to a decline in sexual function and erectile dysfunction; on the other hand, when having sex, nervousness, worry and other psychological states can lead to a lack of concentration and erectile dysfunction. 2. Endocrine diseases: due to the pituitary gland, testes and other pathologies, resulting in endocrine hormone level disorders in the body, which may lead to erectile dysfunction. For example, with the increase of age, testicular function decreases, sex hormone level decreases, can also appear male erectile dysfunction. 3. Vascular lesions: male penile erection mainly depends on the opening and closing of the arteries and veins to realize, such as vascular lesions, can lead to erectile dysfunction, such as arteriovenous fistula. 4. Drugs: some antihypertensive drugs, antidepressants, endocrine therapy drugs can lead to erectile dysfunction. Erectile dysfunction can be caused by many reasons, if you are not feeling well, please go to the regular hospital for treatment.