While men may not suffer hot flashes like women who experience menopause, middle-aged men's bodies do undergo major changes -- including hormonal ones.
At age 50, John Upton said he hit midlife and hit rock bottom.
Upton, a documentary filmmaker and father of four, was newly-divorced and feeling more lost than ever.
"It's like you are looking at yourself, and you don't recognize the person that you are seeing," Upton said.
He began searching for a way out of his rut -- a downward spiral he said left him depressed, overweight and hopeless.
"Some people my age say, 'Well, I'm just going to age gracefully,'" he said. "Obesity, depression, lethargy [and] despair are not graceful qualities in my book."
He learned what he was going through was not a fleeting midlife crisis, but a very real medical condition.
Doctors call it andropause. It's similar to the hormonal drop that most women experience as they grow older, but more gradual.
Men lose about one percent of their testosterone every year, beginning at age 30. Unlike female menopause, which usually runs its course in a matter of years, so-called "male menopause," can last decades.
"What I was seeing was hundreds and hundreds of relationships falling apart at midlife, just when the couples could really be enjoying their lives," Jed Diamond, author of "Male Menopause," said. "The depression that accompanies these kinds of changes can kill men at early ages that don't need to die."
Doctors say millions of American men suffer the symptoms of andropause without even knowing what it is.
Symptoms like fatigue, depression, anger, anxiety, memory loss, relationship problems, loss of sex drive and erectile dysfunction are common and often written off as a normal sign of aging.
Upton's doctors recommended testosterone injections, but mandated that his hormone and blood pressure levels be tested regularly. The shots, he says, gave him a new lease on life.
"I will take the next 10 years as I am, because the way I was in those old pictures, I don't, I wouldn't want to live another 30 years like that," he said.
While prescriptions for testosterone products like injections and gels have tripled in the last few years, they're not for everyone.
"We know that prostate cancer grows in the presence of testosterone," the UCLA Urology Program's Dr. Christopher Saigal said. "When you remove it, the testosterone from the body, the prostate cancer goes away."
But you won't hear any complaints from Upton. Today he's remarried and his new wife Elizabeth Upton reports her husband acts like a man 20 years younger -- even in the bedroom.
Men suffering from the symptoms of male menopause should go their doctors and have them test for active testosterone, which is the kind that can cause symptoms if your numbers are low. Some physicians only measure total testosterone, which may not give the full picture.