The most common signs of low testosterone, from low sex drive to difficulty building muscle, according to doctors

• Loss of libido and fatigue are some of the most common symptoms of low testosterone, doctors say.
• The hormone can also affect your mental focus, mood, and ability to build muscle and strength.

Testosterone is an important hormone for muscle, bone strength, and sexual health, particularly in men.

Low levels of testosterone can cause a range of health symptoms, and a growing number of people are opening up about their experiences and seeking treatment, according to Dr. Elise Brett, an endocrinologist in New York City.

"I think there's increased awareness and patients are more comfortable now than in the past discussing it and asking to be tested," Brett told Insider.

A blood test can determine if you have low testosterone, and rule out other potential explanations for any symptoms.

Potential red flags that you might want have your testosterone levels tested include changes to mood, energy, fitness, focus, and sexual health.

Doctors say decreased sex drive is the most common complaint that leads to testosterone testing

By far the most frequent reason patients ask to be tested for low testosterone is a problem with their sex drive, according to Brett.

However, one day or even a week of low libido may not be cause for concern.

"Typically symptoms occur over the course of several months," she said.

Other potential explanations for short- and long-term loss of sex drive include stress, performance anxiety, and lack of sleep.

Mood changes and symptoms of depression may be hormone-related

Another common symptom linked to low testosterone is a persistent, general sense of reduced wellbeing. Combined with other symptoms, it may be a signal to have your hormones tested.

"I see a lot of men with symptoms of maybe not depression but lower mood, and treatment seems to help," Brett said.

Trouble building or maintaining muscle and strength can also be a symptom

Since testosterone is an important hormone for muscle building, low levels can lead to loss of muscle or strength, or an inability to make gains, according to Dr. Gabe Mirkin, a sports medicine specialist.

However, it's important to get tested, since using testosterone therapy to boost strength and muscle mass when you don't have a deficiency can have unanticipated side effects, Mirkin said.

"If it's normal, you're in no man's land when you take testosterone," he said.

Fatigue or loss of endurance are side effects of low testosterone, too

Patients with low testosterone frequently report having a loss of energy, more fatigue during the day, or an inability to keep up with activities they could previously do, including workouts, both Brett and Mirkin said.

Forgetfulness and brain fog may be a sign to get tested

Another possible symptom of low testosterone is cognitive problems, according to Mirkin. Patients report being absent-minded and having difficulty concentrating, he said.

A healthy lifestyle can help reduce the risk of hormone issues

While there's no sure-fire way to prevent low testosterone, making healthier choices can support healthy testosterone levels, the doctors said.

Maintaining a healthy weight, exercising regularly, not smoking, and avoiding excessive alcohol use can help prevent factors like inflammation that may interfere with your hormones and overall health, according to Mirkin.

"Diet is incredibly important," he said. "Your diet should be loaded with fruits, vegetables, nuts, and seeds, with limited meat, sugar, and fried foods."

If a test determines you have low testosterone, doctors will look for underlying causes, such as other illnesses, Brett said. Treatment can include testosterone replacement via gel, injections, pills, or a patch.

It's important to work with doctors on the proper dose and timing, since therapies can sometimes inhibit your body's ability to produce its own testosterone.

"The longer you take it the more likely you are to be dependent," Brett said.