Testosterone deficiency in older men: a problem worth treating.

Testosterone levels decrease with normal aging, and researchers estimate that more than 4.5 million American men may have symptoms related to low testosterone. Termed late-onset hypogonadism (LOH), low testosterone levels in older men may be associated not only with symptoms such as depressed mood and fatigue, but also comorbidities such as diabetes and heart failure. Understanding the symptoms, diagnosis, and treatment of LOH is important for all practitioners who care for older men.