One leading physical cause of ED is continual or severe damage taken to the nervi erigentes, which can prevent or delay erection. These nerves course beside the prostate arising from the sacral plexus and can be damaged in prostatic and colorectal surgeries. Diseases are also common causes of erectile dysfunctional. Diseases such as cardiovascular disease, multiple sclerosis, kidney failure, vascular disease, and spinal cord injury can cause erectile dysfunction. Cardiovascular disease can decrease blood flow to penile tissues, making it difficult to develop or maintain an erection. Due to the shame and embarrassment felt by some with erectile dysfunction, the subject was taboo for a long time and is the focus of many urban legends. Folk remedies have long been advocated, with some being advertised widely since the 1930s. The introduction of perhaps the first pharmacologically effective remedy for impotence, sildenafil (trade name Viagra), in the 1990s caused a wave of public attention, propelled in part by the newsworthiness of stories about it and heavy advertising. It is estimated that around 30 million men in the United States and 152 million men worldwide have erectile dysfunction. However, social stigma, low health literacy, and social taboos lead to under reporting which makes an accurate prevalence rate hard to determine. The Latin term impotentia coeundi describes the inability to insert the penis into the vagina, and has been mostly replaced by more precise terms. ED from vascular disease is seen mainly amongst older individuals who have atherosclerosis.
Sexual dysfunction is difficulty experienced by an individual or partners during any stage of normal sexual activity, including physical pleasure, desire, preference, arousal, or orgasm. The World Health Organization defines sexual dysfunction as a "persons inability to participate in a sexual relationship as they would wish". This definition is broad and is subject to many interpretations. A diagnosis of sexual dysfunction under the DSM-5 requires a person to feel extreme distress and interpersonal strain for a minimum of six months (except for substance- or medication-induced sexual dysfunction). Sexual dysfunction can have a profound impact on an individuals perceived quality of sexual life. The term sexual disorder may not only refer to physical sexual dysfunction, but to paraphilias as well; this is sometimes termed disorder of sexual preference. A thorough sexual history and assessment of general health and other sexual problems (if any) are important when assessing sexual dysfunction, because it is usually correlated with other psychiatric issues, such as mood disorders, eating and anxiety disorders, and schizophrenia. Assessing performance anxiety, guilt, stress, and worry are integral to the optimal management of sexual dysfunction. Many of the sexual dysfunctions that are defined are based on the human sexual response cycle proposed by William H. Masters and Virginia E. Johnson, and modified by Helen Singer Kaplan. Types
Sexual dysfunction can be classified into four categories: sexual desire disorders, arousal disorders, orgasm disorders, and pain disorders. Dysfunction among men and women are studied in the fields of andrology and gynecology respectively.