By the time Dan hit 57, he didn't recognize himself. He was always tired, fell asleep after dinner and was angry all the time.
"My libido was less and I was beginning to have a loss of erection while having sex, but I thought that was part of the normal aging process," said Dan, who did not want his real name to be used.
"I had just changed doctors and he asked me, 'Are you more grumpy and less interested in things like sex?'" Dan, now a 60-year-old California counselor, said.
"Yeah, I am more grumpy, get less enjoyment out of life and certainly am having less sexual activity with my wife of 40 years," Dan answered. "I had excellent health all my life and he said there was a name for it -- male menopause."
The doctor ordered a series of blood tests and found Dan had low levels of testosterone. "My levels were in the basement," he said.
Dan, according to his doctor, has andropause, what is now euphemistically being called low-T syndrome.
Television ads for low-T syndrome have cropped up on prime-time nightly news programs, joining direct-to-consumer drug ads for erectile dysfunction, or "ED," as well as other aging ailments such as high cholesterol, enlarged prostates and dry eyes.
Andropause is a "term of convenience" in describing the complex symptoms in aging men with low testosterone levels, according to one study at the University of Toronto Department of Medicine.
Some studies show only 25 percent of all men with low testosterone levels ever experience symptoms such as Dan's, as well as bone loss and fracture, sleep disturbances and lethargy.
The very existence of andropause is contentious and large-scale studies on hormone treatment are only a decade old. Many say the underlying cause of some men's complaints are part of the normal aging process.
Two Canadian studies cited by the National Institutes of Health illustrate the debate on low testosterone and its treatment.
Dr. Richard Casey, director of the Male Health Centers in Oakville, Ont., argues that andropause is primarily market-driven, "largely promoted by industry, accepted by a handful of physicians and embraced by some patients who are looking for an antidote to aging."
"We need to resist the marketing efforts and consider the science," writes Casey. "The range of normal testosterone levels is quite broad; levels depend on time of day and no consensus exists on what measurement of testosterone correlates best with symptoms or treatment success."
But Dr. Alvaro Morales of Queens University in Ontario supports the concept of "testosterone deficiency syndrome" (TDS) and advocates well-monitored therapy.
"The absurd view that TDS is an invention of industry blatantly and conveniently ignores medical observations and reports going back 500 years and accelerating since the mid 20th century," writes Morales in his study. "It does not merit further discussion."
"Male menopause is real," said Jed Diamond, a psychologist and author of a series of books on the topic, including, "Irritable Male Syndrome."
"I describe it as adolescence, the second time around," he said. "Everybody goes through it, just as no one can say I didn't go through puberty. Some have a fairly easy time and, for some, it's more difficult."
Part of the normal part of aging, male menopause is accompanied by a gradual decline in their sexuality, mood and overall energy. For most men, it arrives between the ages of 40 to 55, but for some it happens as early as 35 and as late as 65.
"Men are more in denial about this than women," said Diamond, who has a Ph.D. in international health and a master's degree in social work. "It's taken guys a little longer for the medical evidence to come out and for doctors to find ways to treat this. But more men are getting help."
More men are also taking testosterone treatment in creams, gels or injections, Diamond said.
Dan began a holistic course of treatment that included testosterone shots and more exercise, better eating habits, herbal supplements, as well as a multivitamin and zinc.
"Those made a big difference," he said. "But exercise has been the most profound thing. Without it, the other wouldn't work. I do weights and yoga twice a week."
"After a year, the injections worked," Dan said. "It's not like I am doing physical feats that I was not doing before, but I was noticing a change when I would take groceries out of the car and move wood into the pile. Before, I used to groan as I did it and had more aches and pains."
Diamond, who runs the Men Alive Clinic in Willits, Calif., said all men treat menopause differently. Some are in denial and others treat it medically. But male menopause is more complex than just increasing testosterone levels -- involving hormonal fluctuation, changes in brain chemistry, interpersonal and societal changes.
"The changes have to do not only with hormones, but also sex changes that have to do with relationships and self-esteem changes. We evaluate all of these different areas," he said, "We don't just look at the test."
Unlike women's hormone replacement therapy, which uses estrogen from horses, doctors treat men with bio-identical testosterone, Diamond said.
"Biologically, it's the same and it isn't as expensive and they can manufacture it in large quantities," he said.
That's why doctors say the pharmaceutical companies are pushing treatment for low-T syndrome on television. Interestingly, direct-to-consumer advertising is only allowed in two countries in the world -- New Zealand and the United States.
"The drug companies want to figure out new ways of making money," said Dr. Robert Butler, president of the International Longevity Center in New York City and author of the landmark book, "Human Aging."
All men do not experience low testosterone levels, he said. "Not everyone goes through a decline, though there is a small category of men in their 50s and 60s, but it's a new market," he said.
Men should be monitored while taking testosterone because it can cause problems for those with heart conditions or prostate cancer that is underway, Butler said.
"I don't fault [the drug companies] for being good marketers," he said. "But I think the public should beware in terms of endangering themselves."
But Dan said he has confidence in his doctor and, oddly, the regimen has had the least impact on his sex life.
"I don't have to be fearful and anxious and I feel like I am equipped to meet whatever comes my way," he said. "When you are 18 to 20, you think you are immortal. At 30 and 40, you think you have the world by the tail."
"I began to lose that sense for no good reason," Dan said. "Now, I feel a psychological sense of completeness and robustness and maleness."