(CBS) Women aren't the only ones forced to cope with hormonal changes in midlife.
Experts say more than five million men feel the effects of male hypogonadism, a.k.a. male menopause.
And it's no walk in the park. Symptoms of the disorder include mood swings, fatigue, and reduced muscle mass, in addition to a waning sex drive and erectile dysfunction.
What's more, says Dr. Abraham Morgentaler, associate clinical professor of medicine at Harvard Medical School, the condition can raise the risk for heart disease, diabetes, and osteoporosis,
"This is a highly prevalent disorder," Dr. Robert Brannigan, associate professor of urology at Northwestern University Feinberg School of Medicine in Chicago, said in a written statement. "Unfortunately, we estimate that 95 percent of cases are undiagnosed and therefore untreated. When ignored, symptoms can seriously disrupt one's quality of life."
The condition stems from a deficiency of the male hormone testosterone. Men's testosterone levels fall about 1 percent a year beginning in their late thirties, said Dr. Brannigan. By age 70, a guy might be operating with half as much "T" as he had back in the day.
Dr. Brannigan said the condition was increasingly common, adding that men often suffer in silence - needlessly.
The condition can be diagnosed with a simple blood test, and treated with testosterone injections, skin patches and gels, and implantable pellets.
The treatments are controversial, as some evidence suggests that supplemental testosterone raises a man's risk of prostate cancer, according to doctors from the Mayo Clinic. But Dr. Brannigan and Dr. Morgentaler are strong advocates for testosterone replacement, saying that men who get it often experience dramatic improvements in their quality of life.
Says Dr. Brannigan, "This disorder is not something that should be ignored."