Diabetes can have a profound effect upon a person’s sexual drive, functioning, and satisfaction. This is especially apparent in men, although there is some evidence that some women with diabetes can also experience adverse effects on their sexual responses. The reason for the significant effects on male sexual function arises from the complexity of the penile erec- tion mechanism. This requires satisfactory nerve, blood vessel, and hormone function to be achieved and sustained. Diabetic nerve damage can be of two main types. One form is damage to the system that serves conscious movement and sen- sation and the other is damage to the system that serves unconscious or automatic responses, such as bowel contraction and the heart beat. The erectile mechanism is served by the latter, while the sensation of pleasure in sexual performance is served by the for- mer. Since the nerves to the genital area are relatively lengthy, they are prone to the damage described in Normal erectile function also depends on a healthy blood supply to the penis, as erection entails engorgement of the organ with blood. If the blood supply is compromised, the quality of the erec- tion will be poor. As discussed in Question 35, vascu- lar damage is commonly associated with diabetes and frequently affects the health of the vessels supplying the genitals. Finally, normal levels of the male hor- mone testosterone are necessary not only for sexual interest (libido), but also for perception of pleasura- ble sensations from sexual arousal. Low testosterone levels, already common in middle-aged and older men, are even more common in men with diabetes. Indeed, there is suggestive evidence that low testos- terone levels may contribute to worsening of diabetes, thus creating a vicious cycle that further depresses hormone levels. In light of the three strikes of dia- betic nerve damage, vascular damage, and diminished levels of male hormone, it is not surprising that poor sexual performance and diminished satisfaction are a frequent finding in men with diabetes. Indeed, more than half of all men with type 2 diabetes of five or more years’ duration will complain of one or more symptoms of sexual dysfunction. Sometimes this is worsened by medications commonly used by people with diabetes, such as certain blood pressure-lowering drugs.