The perineum is the area between the anus and the base of the penis in males and between the anus and the vagina in females; it contains both blood vessels and nerves. Compression of the perineum can lead to nerve damage, swelling, artery insufficiency (lack of blood flow through the vessel), and even occlusion (blockage) of blood vessels, which in turn can lead to temporary or permanent groin numbness, tingling sensations, decreased penile blood supply, erectile dysfunction (impotence), decreased orgasm sensitivity, and pain. These cycling-related perineal symptoms are the subject of this article.