Younger Than 50? Yes, You Can Have Low Testosterone

Find out why low testosterone symptoms such as fatigue and low libido can occur in younger men.

By Elizabeth Shimer Bowers

Medically reviewed by Pat F. Bass III, MD, MS, MPH

There’s a good reason guys go girl-crazy in their teens and twenties: Their testosterone levels are at their peak. From there, though, testosterone levels slowly decrease.

“After age 30, most men begin to experience a gradual decline in testosterone,” says David Samadi, MD, chairman of the urology department at Lenox Hill Hospital in New York City.

Although testosterone levels never reach zero (as estrogen levels do in women during menopause), the levels can drop too low, causing men to experience symptoms such as fatigue, low sex drive, and loss of muscle mass.

While low testosterone is more common in older men, it can occur in younger men as well. Fortunately, all of the causes of low testosterone in young men are treatable, so if you experience such symptoms at any age, there’s no reason to ignore it.

Causes of Low Testosterone in Younger Men

For younger men, a drop in testosterone levels can be caused by some illnesses, including type 2 diabetes, chronic liver or kidney disease, COPD or other lung disease, or pituitary gland problems, according to Dr. Samadi.

Genetic causes of low testosterone in men include the diseases Klinefelter syndrome, Kallmann syndrome, Prader-Willi syndrome, and Myotonic dystrophy. Another disorder that can cause low testosterone is hemochromatosis, which makes the body store too much iron.

“Low testosterone can also result when something happens, like trauma or steroid use, that prevents the testes from making the hormone,” says Bruce Gilbert, MD, PhD, an adjunct clinical professor of urology and reproductive medicine at Weill Cornell Medical College and director of reproductive and sexual medicine at the Smith Institute for Urology of the North Shore-LIJ Health System.

Other causes of low testosterone in men younger than 50 include pituitary gland tumors, HIV infection, and radiation treatment or chemotherapy for cancer.

Doctors categorize causes of low testosterone as primary or secondary. “Primary hypogonadism stems from a problem in the testicles," Samadi says. "This could be from a developmental issue, injury to the testicles, or radiation or chemotherapy treatment. In secondary hypogonadism, the testicles are normal but function improperly because of a problem with the hypothalamus or pituitary gland.”

Is It Low Testosterone?

Regardless of the cause, low testosterone symptoms are the same. “Symptoms include low libido, erectile dysfunction, fatigue, decreased mental acuity, and moodiness,”Dr. Gilbert says. “Younger men with low testosterone usually come to me and say, ‘I can’t work out like I used to, and I’ve lost interest in sex.’ ”

If you suspect low testosterone, the first step is to see your primary care physician. Your doctor can diagnose low testosterone with a blood test. If your blood test reveals low testosterone (usually defined as a level lower than 300 ng/dL), the doctor may treat you or refer you to a specialist, such as an urologist or endocrinologist.

Treatments for Low Testosterone in Younger Men

Not everyone with low testosterone needs treatment. "When it comes to treating low testosterone in younger men, we usually reserve treatment for those who have symptoms, such as fatigue and low libido," Gilbert says.

In men who don’t make the hormone in their testes because of a condition such as Klinefelter syndrome, or those who have lost their testes because of cancer, the only option is testosterone replacement therapy. Such testosterone supplements come in the form of a gel, injections, patches, long-acting pellets, or oral inserts.

In these circumstances, “treatments are usually used only in the short term, and when a doctor has close observation and knowledge of the patient,” Gilbert says.

An important consideration for younger men before getting treatment is fertility.“You don’t want to give supplemental testosterone to men who want to be fertile because it can turn off sperm production,” Gilbert says.

Once a young man goes off testosterone supplementation, there’s a chance his sperm count will never return to what it was before he started. “Therefore, men of reproductive age should consider alternatives that might increase their testosterone as well as preserve their sperm production,” he says. One such alternative is a class of drugs called selective estrogen receptor modulators (SERMs).

Other treatments for low testosterone include weight loss and other lifestyle changes, such as eating healthier and increasing exercise.

The bottom line, though, is that if you have low testosterone symptoms, it’s important to see your doctor. Then, your doctor can rule out potentially more serious causes of your symptoms, such as high blood pressure or a thyroid problem, and offer treatment that can improve your energy and quality of life.