Community surveys and studies of patients in medical and sex therapy clinics, summarized in Chapter 8, make abundantly clear the high prevalence of medical illnesses associated with erectile disorders in aging men. Any illness that is accompanied by weakness, fever, pain, malaise, and limited mobility is likely to have a generalized, nonspecific effect on sexual function. Medical disorders may also have direct actions by interfering with vascular, neural, and endocrine processes that mediate the sexual response. Their sexual effects are frequently multifactorial, involving physiological mechanisms interacting with psychological processes. Aging contributes significantly to the nature of this interaction; a person's age not only influences the probability of being affected by a specific illness but also determines their biobehavioral response to the medical problem (Mulligan, 1989). The effect of illnesses on individual sexual responses is also influenced by factors such as prior experiences of, and attitudes to, sex, coping styles, personality characteristics, and the nature of ongoing relationships. Regretfully, little empirical, systematic data on these critically important aspects are available for determining the effect of illness on sexual satisfaction.

A wide range of chronic organic conditions are associated with male sexual disorders (Table 9.1). The following is a discussion of the most prevalent diseases and surgical interventions that affect the sexual life of aging men. Coping and adaptive responses, as well as diagnostic and management issues will be considered in subsequent chapters.