Blue balls is a slang term for a temporary fluid congestion in the scrotum and prostate region. It is most commonly associated with adolescents but can occur in any sexually mature male. It is often accompanied by a deep, agonizing, cramping ache.
The main cause of blue balls is prolonged sexual stimulation of the erect penis, either by direct or indirect contact, that does not result in orgasm and ejaculation.
During arousal in a sexually mature male, the sympathetic nervous system is disrupted, resulting in increased blood and lymphatic fluid flow to the scrotum, testicles and prostate areas. As this happens, other fluid outflow muscles constrict, causing more bodily fluid to enter the area than leave, ensuring a high enough regional blood pressure to allow a sustained erection for penetration during sexual intercourse.
Because orgasm is not achieved, the blood tends to pool and become oxygen deprived. In some men, this pooling of oxygen-starved blood may result in a bluish tint to the scrotum.
The easiest way to relieve the symptoms of blue balls is through an orgasm either by masturbation or sexual intercourse. The resultant ejaculation jump-starts the sympathetic nervous system, which increases blood flow through the groin area, dissipating the fluid buildup. Even without orgasm, the symptoms of blue balls usually subside within an hour of onset. The symptoms can also last much longer.
One folk remedy for blue balls is the cold shower, which stimulates increased blood flow throughout the body, including the groin area.
Men with priapism or orchalgia may experience an extreme, prolonged form of blue balls, which may require medical attention.
Women can also experience discomfort due to unrelieved vasocongestion as their genitals also become engorged with blood during sexual arousal. They can experience pelvic heaviness and aching if they do not reach orgasm.