Typically, a man's testosterone level is considered low if it's below 300 ng/dL. Low T can be caused by a signaling problem that occurs between the brain and the testes that causes the production of testosterone to drop below normal. Low T also can occur when your body can't make normal levels of testosterone. Low T is a medical condition that can lead to fatigue or low energy, decreased sexual function, and depressed mood.

Low T affects more than 13 million men in the U.S. over the age of 45. Even though it's natural for men to lose testosterone as they age, the medical condition hypogonadism (hī pō gō na dizm), also known as Low T, is not a natural part of aging. Common symptoms include lack of sex drive, low energy and decreased sense of well-being. There is no cure for Low T. It is a medical condition that requires ongoing treatment.

The good news is, it can be easily diagnosed by your doctor with a simple blood test and treated with testosterone replacement therapy (TRT) to raise your T levels back to normal.