Low testosterone is an incredibly common problem amongst middle-aged men. It’s estimated that nearly 40% of men over the age of 45 in the U.S. have a testosterone deficiency. So why is low T so common?

Testosterone deficiency, or hypogonadism, comes in different forms. Primary hypogonadism means there is a problem with the testicles (or testes) themselves. The body is producing hormones to stimulate testosterone production, but for some reason, the testes are not responding. This can be due to congenital abnormalities and genetic conditions, testicular injury, radiation therapy, certain medications, and environmental toxins.

Secondary hypogonadism means the testicles work fine, but there is a disruption in the hormonal signal that tells them to produce testosterone, so they can’t. This is due to a problem with the pituitary gland or the hypothalamus, which can be caused by congenital abnormalities, opioid use (74% of chronic opioid users have low T), traumatic brain injury, benign brain tumors, cancer, malnutrition, and chronic diseases like diabetes, obesity, hypothyroidism, cirrhosis, HIV, and sleep apnea.

However, about 89% of men who have low T do not fit into either of these categories! They might have some of the conditions listed above, but they don’t have abnormal levels of pituitary hormones (like FSH and LH). They have what is known as “adult-onset hypogonadism.” It’s associated with aging but is really more about chronic inflammation in the body, rather than just aging itself. This is why even younger men can have low testosterone, even though they seem otherwise healthy. Low T can be a warning signal of health problems developing in the future.

Chronic inflammation happens as a result of medical conditions or lifestyle practices that essentially destabilize the natural functioning of the body–for example, atherosclerosis, high blood sugar levels, eating unhealthy foods, nutrient deficiencies, “leaky gut” syndrome, food sensitivities, smoking, excessive alcohol use, being overweight, and not getting enough sleep. These conditions are extremely common in modern society.

Excess body fat is a major cause of low testosterone because fat produces estrogen. This counteracts testosterone production and leads to low T. The low testosterone then makes this problem worse by increasing fat. The good news is, testosterone replacement therapy can help to interrupt this vicious cycle and aid in weight loss, improved insulin sensitivity, and reduced cholesterol levels.