Impotence, often referred to as erectile dysfunction, is sexual dysfunction characterized by the inability to develop or maintain an erection during sexual performance. Unlike other conditions that interfere with sexual intercourse such as lack of sexual desire or decreased libido and problems with ejaculation and orgasm, impotence can range in severity from men not being able to achieve an erection, to others who have an inability to those who can only sustain brief erections. It is a common problem among men and the risk for it increases with age.

According to the Journal of Urology, men in their 60s are more likely to suffer from impotence than those in their 40s, and also those with less education are more likely to experience it (possibly because they tend to have less healthy lifestyles, eat a less healthy diet, drink more, and exercise less). Causes of impotence can be either organic and physical or psychological. They include: drugs, neurogenic disorders, cavenosal disorders, psychological causes (such as performance anxiety, stress, negative feelings, or mental disorders including clinical depression and panic disorders), surgery, ageing, kidney failure, diabetes, multiple sclerosis, and lifestyle choices (i.e. smoking is a key cause of erectile dysfunction). It can be diagnosed via a variety of tests, including: duplex ultrasound, penile nerves function, nocturnal penile tumescence, penile biothesiometry, dynamic infusion cavernosometry, corpus cavernosometry, and magnetic resonance angiography.

impotence can be treated in a number of ways. First, it is important to discover the underlying cause. These can range from potassium deficiencies to arsenic contamination of drinking water, or one of the others previously mentioned. Treatments for impotence include medications such as phosphodiesterase type 5 inhibitors, alprostadil, and gene therapy, injection therapy with drugs such as papaverine and phentolamine, surgery, and devices including vaccum therapy. Alternative therapies are also available, although not recommended by the FDA.