Characterized by the persistent or recurrent partial or complete failure to attain or maintain the lubrication-swelling response of sexual excitement until the completion of the sexual act. A subjective sense of arousal is often poorly correlated, however, with genital lubrication in both dysfunctional and normal women. A woman complaining of lack of arousal may lubricate vaginally, but may not experience a subjective sense of excitement. Some studies using functional magnetic resonance imaging (fMRI) have revealed a low correlation between brain activation in areas controlling genital response and simultaneous ratings of subjective arousal. Physiological studies of sexual dysfunctions indicate that a hormonal pattern may contribute to responsiveness in women who have excitement-phase dysfunction. Alterations in testosterone, estrogen, prolactin, and thyroxin levels have been implicated in female sexual arousal disorder. Also, medications with antihistaminic or anticholinergic properties cause a decrease in vaginal lubrication.
Male erectile disorder is also called erectile dysfunction and impotence. A man with lifelong male erectile disorder has never been able to obtain an erection sufficient for vaginal insertion. In acquired male erectile disorder, a man has successfully achieved vaginal penetration at some time in his sexual life but is later unable to do so. In situational male erectile disorder, a man is able to have coitus in certain circumstances but not in others; for example, he may function effectively with another woman but be impotent with his wife. Acquired male erectile disorder has been reported in 10 to 20 percent of all men. Impotence is the chief complaint of more than 50 percent of all men treated for sexual disorders. Male erectile disorder, however, is not universal in aging men; having an available sex partner is related to continuing potency, as is a history of consistent sexual activity and the absence of vascular disease. Male erectile disorder can be organic or psychological or a combination of both. In an ongoing relationship, impotence may reflect difficulties between the partners, particularly when a man cannot communicate his needs or his anger in a direct and constructive way. In addition, episodes of impotence are reinforcing, with the man becoming increasingly anxious before each sexual encounter. A number of procedures, benign and invasive, are used to help differentiate organically caused impotence from functional impotence. The procedures include monitoring nocturnal penile tumescence (erections that occur during sleep), normally associated with rapid eye movement; monitoring tumescence with a strain gauge; measuring blood pressure in the penis with a penile plethysmograph or an ultrasound (Doppler) flowmeter, both of which assess blood flow in the internal pudendal artery; and measuring pudendal nerve latency time. Other diagnostic tests that delineate organic bases for impotence include glucose tolerance tests, plasma hormone assays, liver and thyroid function tests, prolactin and follicle-stimulating hormone (FHS) determinations, and cystometric examinations. Invasive diagnostic studies include penile arteriography, infusion cavernosonography, and radioactive xenon penography. Invasive procedures require expert interpretation and are used only for patients who are candidates for vascular reconstructive procedures. Organic Reasons can be either decreased blood supply to the penis, decreased testosterone or defective endothelium, all of which can be treated.