"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 like fatigue, low libido, and loss of muscle mass.
While reduced testosterone is more common in older men, it can occur in younger guys as well. Fortunately, all the causes of low testosterone in young men are curable, so in the event that you experience such symptoms at any age, there is no reason to dismiss it.
For younger men, a drop in testosterone levels can be caused by some ailments, such as type 2 diabetes, 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. 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 would be 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 a urologist or endocrinologist.
"When it comes to treating low testosterone in younger guys, we generally reserve treatment for those who have symptoms, such as fatigue and low libido," Gilbert says.
In these circumstances,"therapies are usually used just in the brief term, and when a physician has close observation and understanding of the patient," Gilbert says.
An important consideration for younger men before getting treatment is fertility. "You do not wish to give supplemental testosterone to guys who want to be fertile since 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. "Hence, men of reproductive age should consider alternatives that might improve their testosterone in addition to preserve their semen production," he states. One such choice is a category of drugs called selective estrogen receptor modulators (SERMs).
Other treatments for low testosterone include weight loss and other lifestyle modifications, such as eating healthier and raising exercise.
The main point, however, is that if you've got low testosterone symptoms, it's very important to see your physician. Then, your doctor can rule out potentially more serious causes of your symptoms, such as hypertension or a thyroid problem, and give treatment that could improve your energy and quality of life.