Normal Aging vs. Low Testosterone

Learn some of the lesser-known signs of low testosterone.

Fatigue is a common symptom of low testosterone.

Medically reviewed in April 2021

As men age, they experience symptoms like decreased muscle mass, reduced energy levels and weight or body fat fluctuations. But when are these symptoms considered normal signs of aging versus a more serious health condition like low testosterone?  

Low T, or hypogonadism, occurs in 10 percent of men between ages 40 and 60, and 20 to 30 percent over 60, according to Christopher Starks, MD, a urologist and men’s sexual health expert with StoneSprings Hospital Center in Dulles, Virginia. 

When does testosterone drop? 

Dr. Starks says he begins thinking about treatment for low testosterone when a man’s levels fall below 350 nanograms per millimeter (ng/ml), but beyond that, it’s tough to tell when hypogonadism begins to take hold. “One of the things that’s very difficult when you’re talking about low T is that there’s no specific age range,” says Starks. It may depend on your baseline levels, which are different for every man, he says. 

Not only are everyone’s base levels of testosterone different, but a number of factors can change levels in the same man, too. A 2012 study published in the Journal of Andrology of nearly 11,000 men found that their testosterone levels were, on average, at their highest in spring and lowest in fall. Daily fluctuations happen too—testosterone surges late at night and into the early morning hours. 

Causes and onset 

Starks says there are a number of potential causes beyond age. Certain injuries to the testicles or testicle removal can cause a drop in testosterone. So can drug use—opioids, marijuana and alcohol can also cause hypogonadism, as can prescription medication like steroids and some antidepressants. Diabetes, depression and systemic illnesses like HIV are other possible causes. “Obesity is certainly a risk factor,” adds Starks. 

When it comes to low testosterone, the signs rarely appear all at once, says Starks. “I typically find a slower, more insidious onset,” he says. “It’s rare that libido goes from normal to low in a month.” 

Telltale signs of low T 

A change in libido is the most telling symptom, according to Starks. “If someone says his libido has dropped and that is in concert with a lab value of lower testosterone, I take that seriously,” he says. Other sexual symptoms of low T include fewer erections, a lower sperm count and changes in testicle size. 

How you can tell if you have low testosterone 

Pay attention to your body. Have you gained a little flab last year despite sticking with a healthy diet? Do weights in the gym or objects around the house feel heavier? Fat gain and muscle and strength loss could be signs of low T, as can osteopenia and bone pain—so take care of your bones

Other symptoms, like depression, fatigue and trouble sleeping or concentrating, are a little harder to spot. “There are a number of conditions that can masquerade as low T,” Starks says. 

Treatment options 

Starks begins thinking about treatment when he finds both symptoms and low lab test levels. “If the testosterone levels are, say, 305 ng/ml, but energy and libido are great, then that might be normal for that man,” he says. 

Testosterone replacement therapy (TRT) may be right for men who don’t want any—or any more—children. Taking an outside source of testosterone will get your levels up, but at the cost of sperm production. Human chorionic gonadotropin (hCG) may be a better alternative for men who want to have children. 

Beware of fitness magazine and website ads for supplements that claim to raise testosterone. “I don’t think there are many foods or dietary supplements that will raise testosterone,” says Starks. “There’s not much you can take orally that’s going to significantly impact testosterone levels.” 

Eating right and exercising will help, according to Starks. It’s important to keep your weight and fat levels down. “Fat tissue really burns through testosterone,” says Starks. “It converts testosterone to estrogen and at a very high rate.” Keep the weight off, says Starks, and you can add “more testosterone” to the list of benefits of a good diet and enough exercise.

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