"After age 30, most men begin to experience a gradual decline in testosterone," states 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), low testosterone levels men to experience symptoms such as fatigue, low sex drive, and reduction of muscle mass.
While reduced testosterone is more prevalent in older men, it may occur in younger guys as well. Fortunately, every one of the causes of low testosterone in young men are treatable, so if you encounter these symptoms at any given age, there's no reason to dismiss it.
For younger guys, a fall in testosterone levels can be brought on by some illnesses, including type 2 diabetes, diabetes, chronic liver or kidney disease, COPD or other lung disease, or adrenal gland problems, according to Dr. Samadi.
Genetic causes of low testosterone in males include the diseases Klinefelter syndrome, Kallmann syndrome, Prader-Willi syndrome, and Myotonic dystrophy. Another disorder which could result in low testosterone is hemochromatosis, which makes the body shop 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 reproductive medicine in the Smith Institute for Urology of the North Shore-LIJ Health System.
Additional causes of low testosterone in males younger than 50 include pituitary gland tumors, HIV infection, and radiation therapy or chemotherapy for cancer.
Doctors categorize causes of low testosterone as secondary or primary.
"Primary hypogonadism stems from a problem in the testicles," Samadi says. In secondary hypogonadism, the testicles are normal but function improperly because of a problem with the hypothalamus or pituitary gland."
Is It Low Testosterone?
Irrespective of the cause, low testosterone symptoms are the same.
"Symptoms include low libido, erectile dysfunction, fatigue, decreased mental acuity, and moodiness," Dr. Gilbert states.
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
"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.
In these circumstances,"treatments are usually used only in the brief term, and if a physician has close monitoring and understanding of the individual," Gilbert says.
An important consideration for younger men before getting treatment is fertility. "You do not want to give supplemental testosterone to guys 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, then it is very important to see your physician. Then, your doctor can rule out potentially more significant causes of your symptoms, such as hypertension or a thyroid problem, and give treatment that could improve your energy and quality of life.