What Are the Many Potential Causes of Low Testosterone?

Discussions around low testosterone often focus on the symptoms of low-T.

Conversely, you sometimes hear exclusively about what you're missing out on due to suboptimal testosterone levels. The conversation immediately shifts toward what testosterone replacement therapy (TRT) may be able to do for you: better energy, improved mood, improved sex drive, better lean muscle-to-fat ratio and better erectile function.

Unfortunately, the modern tendency to look for quick-fix pharmacological solutions leads people to overlook the underlying causes of a medical issue. They get into a big rush to alleviate the symptoms in the quickest, easiest way possible.

That's especially true for the delicate natural hormonal balance in the body. It requires careful calibration to function correctly. It's not like taking an antibiotic for a bacterial infection.

Coming at testosterone with a sledgehammer of clumsy, inexpert or poorly thought-out "treatment" can be disastrous, especially if you don't try anything else first.

For that reason, most reputable men's health specialists don't go directly to TRT. They begin any conversation about potential low-T symptoms with a thorough assessment of the patient's history and lifestyle. They want men to understand they have a great deal of control over their own testosterone levels.

As with any condition, it's important to know the causes of low testosterone and how aging may or may not affect testosterone production. Let's dive into that information and look at a set of possible testosterone-related behaviors that's been dubbed "irritable male syndrome."

What are the causes of low testosterone?

On an abstract level, many people realize that modern Western life is unhealthy. The types of food we eat, the level of exercise many of us choose, the type and amount of substances we take—hell, the very air we breathe—all of these things conspire to compromise our health across a variety of bodily systems.

Look at a typical American man's lifestyle through the lens of testosterone production and it really snaps into focus.

Obesity

Let's start with one of the biggest impediments to testosterone production and general health in modern life: obesity. As of 2018, more than 42 percent of American adults were obese, and 30.7 percent were overweight. About 1 in 11 adults were severely obese, meaning they had a body mass index (BMI) of 40 or higher, according to the National Institutes of Health (NIH).

Obesity leads to more adipose tissue, or body fat. That excess fat is thought to convert testosterone to estrogen, thereby decreasing testosterone levels. The process itself is more complicated than that, but at its base, excess fat hinders testosterone production.

Multiple studies show a strong link between obesity and low-T. The connection is clear.

One 2017 study featured a man who was morbidly obese and hypogonadal (low-T). He underwent a gastric bypass procedure and his testosterone returned to normal levels so completely that he was taken off exogenous testosterone, according to the researchers.

This study, albeit with a sample size of just one, dovetails with a 2019 review of obesity and low-T. That research suggested that obesity leads to low-T, but the opposite is also true: Low testosterone can cause increased fat accumulation.

Diabetes

Diabetes is closely linked to obesity, and the two of them together are a warning sign of low-T. A certain portion of men with erectile dysfunction (ED) can be expected to have hypogonadism, according to the NIH, but that number increases if those men are obese or have diabetes.

Sleep apnea

Sleep apnea becomes more common in men as they reach middle age, and this condition may exacerbate the natural drop in testosterone production that occurs with age. Simultaneously treating obstructive sleep apnea and low-T can help, according to the NIH.

Drugs and alcohol

Excessive alcohol consumption and chronic use of drugs, particularly opioids, can impact testosterone production in a significant way.

"The big one for medication is going to be opioids," said Amy Pearlman, M.D., a men's health specialist and co-founder of Prime Institute in Fort Lauderdale, Florida. "Opioids that people use for pain can drastically reduce testosterone levels. I don't know if taking them just for a couple of days can impact testosterone, but I do know that patients who are on them chronically have very low levels, and that's supported by the research."

Aging and testosterone production

Men's testosterone production begins to decline by about 1 percent per year after age 30 or so. This sounds like a damning figure, but there's more to unpack here before you rush off to the clinic the day after you turn 30.

"Yeah, testosterone goes down as people get older, but that doesn't mean it's going to be low—if they keep themselves healthy," Pearlman said. "Some of my healthiest patients that come in are in their 80s and 90s and are hoping they have low-T because they have some fatigue or they're not as sharp as they were before. They're hoping their testosterone level is low so I can put them on testosterone and they can go live their best lives.

"I find that the people who are moving and grooving and staying active and treating their bodies well, just because they're 80 or 90 years old doesn't mean they're going to have low testosterone," Pearlman added.

Another important point: That 1 percent drop in testosterone per year may sound like a slow death sentence to your libido, but in the grand scheme of things, it's not a lot.

"One percent is not that much," Pearlman said. "So if someone has total testosterone of 600 nanograms per deciliter, then 1 percent is going to be 6 nanograms per deciliter per year."

'Irritable male syndrome'

Researchers are connecting the dots between the proven scientific phenomenon of lower testosterone production in older men and the anecdotal evidence that some older men become more irritable and depressed and have lower self-confidence and less energy. They're calling it "irritable male syndrome," but it is strongly linked to what's clinically called "andropause" or sometimes "male menopause."

Now, it's safe to say we should take that clickbait-heavy term with a grain of salt.

What is indisputable is that the normal age-related reduction in androgen production—androgens are "male" hormones, such as testosterone—is linked to moodiness and the other symptoms mentioned above.

One study on irritable male syndrome looked at the end of mating season for a species of ram called the Soay ram. Researchers found the drop in testosterone production at the end of the mating season resulted in the animals appearing to be more fearful and agitated.

What was also striking was that they fought more, resulting in more frequent physical wounding.

Low testosterone is often reversible

Ultimately, testosterone production is something you can control to some degree.

You can't stop aging, but you can get more active, eat healthier, cut drug and alcohol use, and lose excess weight. Doing these simple things can help you stay "moving and grooving" well into old age like one of Pearlman's 80- or 90-year-old, active, healthy patients with great testosterone levels.

Eating better and exercising more may not be a quick fix, but it's a sustainable, healthy way to start your journey to optimal testosterone levels and feeling better in general.