With tens of millions of Americans in middle age, “menopause” is an everyday word — and it almost always is used in reference to women.

But medical experts say women aren’t alone in this regard — “male menopause” affects millions.

Its medical name is “andropause,” defined as the aging-related hormone changes in men, and its symptoms come on much more gradually than what women experience.

As a matter of fact, the symptoms may not be noticed for years, and that may be one of the reasons men do not seek treatment as often, said Dr. Evan Goldfischer of Hudson Valley Urology.

“In general, women lead the health charge in the family. They’re much more pro-active in being screened and in taking care of themselves,” Goldfischer said. “Men lag behind the curve. They’re not as apt to come in.”

Andropause is also called testosterone deficiency and androgen deficiency. It affects 25 million American males between 40 and 55, a number that surely will increase in the years to come as the huge baby boomer generation ages, according to the Mayo Clinic.

In men, testosterone helps maintain bone density, fat distribution, muscle strength and mass, red blood cell production, sex drive and sperm production.

Andropause symptoms can include low energy, loss of concentration, depression, changes in sexual function, mood swings and depression, changes in sleep patterns, increased body fat and decreased bone density, the Mayo Clinic said.

Testosterone levels vary greatly in men, but in general, levels gradually decline about 1 percent a year after age 30. By age 70, the decrease can be as much as 50 percent.

Though menopause in women and andropause in men are both caused by hormone change, that’s where similarities end.

In men, subtle sex hormone changes occur over a longer period of time. In women, ovulation ends and hormone production levels plummet over a shorter period.

And though the news media and marketing for health products have made “erectile dysfunction” a household word, it can still be difficult for men to seek treatment for any kind of condition related to sexual dysfunction, Goldfischer said.

“They’re embarrassed. They kind of shrug it off,” Goldfischer noted, but encouraged middle-age men to speak to their physicians about health changes that may be subtle but make a significant impact in their lives. He also said not all patients with erectile dysfunction have andropause, which is a broader syndrome. Diabetes and medications for hypertension and other conditions can cause erectile dysfunction.

According to the National Institutes for Health, aging itself does not prevent a man from being able to enjoy sexual relationships.

Sexual responses may become slower and less intense, which can be related to andropause but also from psychological or social change related to aging, such as lack of a willing partner or chronic conditions, according to the NIH.

Fertility varies and age is not a good predictor. Prostate function is not closely related to fertility and fairly old men can father children.

Blood tests can diagnose andropause and hormone replacement therapy can be a treatment option, said Goldfischer, adding that patients choose from injections, patches or gels.

As for risks, Goldfischer said there is no evidence hormone replacement therapy causes cancer, but there is a risk it could exacerbate the growth of a pre-existing tumor. Those concerns should be discussed with a doctor and patients who are on hormone replacement therapy should be checked regularly for side effects.

Goldfischer warned against believing solicitations for herbal supplements and “natural remedies.” “There’s no evidence that they actually work,” he said.

It is not clear if hereditary factors, environment or lifestyle are associated with andropause. And it’s believed that low testosterone levels can predispose men to health problems such as heart disease and osteoporosis, according to medical experts.

Men are encouraged to see a doctor about a blood test to diagnose low testosterone levels. The Mayo Clinic noted that while some symptoms of andropause are a normal part of aging, others could be caused by medication side effects, thyroid problems, depression and excessive alcohol use.

They are also encouraged to lead a healthy lifestyle with regular exercise, which can promote better sleep, boost someone’s mood and help maintain strength and lean muscle mass.

Goldfischer said he has treated many patients with hormone replacement therapy and hopes their overall good outcomes will encourage other men to seek treatment for andropause symptoms.