Difficulty in erection and not hard enough may be erectile dysfunction. Common causes include organic causes, psychological causes, mixed causes and other causes. Erectile dysfunction is also known as impotence. Erectile dysfunction mainly manifests itself in the frequent inability to have a normal erection, or the erection is not hard enough to complete sexual intercourse, or the erection time is too short to complete sexual intercourse. 1. Organic causes: such as penile vascular dysfunction, central nervous system disease, penile curvature, hypogonadism may lead to erectile dysfunction. 2. Psychological causes: such as daily disharmony between husband and wife, asymmetry or lack of sexual knowledge, adverse sexual experiences, work or economic pressure, incorrect understanding of media publicity, fear of disease and adverse drug reactions, etc. can cause erectile dysfunction. 3. Mixed causes: Erectile dysfunction may be caused by one or more diseases and other factors, common such as diabetes mellitus, hypertension, trauma and other primary diseases, as well as social and environmental factors, mental and psychological, lifestyle and so on. 4. Other causes: drugs may trigger erectile dysfunction, such as antipsychotics, antidepressants and drugs. Patients should go to the hospital in time to avoid delaying their condition or triggering adverse reactions.