Testosterone has a big influence on men’s bodies. It affects muscle mass, metabolism, and sexual function, and also contributes to daily energy levels, mood, and vitality.
If testosterone drops below healthy levels, it is often referred to as low testosterone, or low-T.
Low-T becomes more common as men get older, but it can happen at any stage of life. Natural aging can lower testosterone, but medical and lifestyle factors play a role, too.
What Causes Low Testosterone In Men?
1. Natural aging
A gradual decline in testosterone is a normal part of aging. Starting around age 30, testosterone levels typically fall about 1% per year. By the time men reach their 60s or 70s, testosterone levels are often quite a bit lower than in younger adulthood.
Overall, age-related decline is the most common cause of low testosterone. However, not every man develops symptoms significant enough to need treatment. For some men, fatigue, reduced muscle mass, weaker bones, and changes in sexual function become hard to ignore.
2. Extra bodyweight and metabolic health
Carrying excess body fat, especially around the abdomen, is strongly linked to lower testosterone levels. Increased fat tissue raises levels of aromatase. This enzyme changes testosterone to other compounds, leaving less available for the body’s normal functions.
Having a high body weight also contributes to insulin resistance, type 2 diabetes, and inflammation. All of these conditions can suppress signals that drive testosterone production.
3. Chronic illness
Many chronic medical conditions can interfere with production. For example:
- Type 2 diabetes alters the body’s sensitivity to insulin and affects how the brain signals testosterone release
- Chronic kidney disease and liver disease change how hormones are metabolized and cleared
- Chronic inflammation further suppresses testosterone
4. Testicular injury or surgery
The testes are the main site of testosterone production. Any injury or infection can directly reduce hormone output.
- Trauma or torsion may permanently damage testicular tissue
- The removal of one or both testes, sometimes done because of cancer, sharply decreases testosterone
- Mumps orchitis, a complication of the viral infection mumps, can cause long-term testicular damage
5. Pituitary and hypothalamic disorders
The brain controls testosterone through a hormone cascade.
When the pituitary or hypothalamus is damaged, the signal is interrupted, and testosterone drops. These causes are less common but important because they can sometimes be corrected with treatment:
- Pituitary tumors may block hormone release
- Head trauma, surgery, or radiation can disrupt the signaling pathway
- Kallmann syndrome, a rare genetic condition, impairs hypothalamic development and results in very low testosterone from puberty onward
6. Medications
Some types of medications that can lower testosterone:
- Opioid painkillers suppress hormone signaling in the brain
- Glucocorticoids reduce hormone production when used for a long time
Medication-related low testosterone often improves if the drug can be reduced or discontinued under medical guidance.
7. Sleep disorders
Disrupted sleep affects hormone release. Testosterone levels peak during deep sleep, in the early morning hours. Both chronic insomnia and sleep apnea can affect hormone rhythms.
8. Stress and excess cortisol
High, sustained stress increases the production of cortisol, the body’s primary stress hormone. Emotional stress, chronic anxiety, or prolonged illness can all elevate cortisol. This leads to a reduction in testosterone’s effects in tissues.
9. Lifestyle factors
Lifestyle habits like poor nutrition, physical inactivity, and chronic lack of exercise may all lead to reduced hormone production over time.
10. Cancer treatments
Hormone therapy used in prostate cancer treatment intentionally suppresses testosterone to slow cancer growth.
See A Doctor About What Causes Low Testosterone in Men
Low testosterone doesn’t have a single explanation. It can be due to aging, lifestyle, chronic conditions, injuries, medication, or even stress and sleep disruption.
If you’re experiencing low-T symptoms, a simple blood test can check testosterone levels. An experienced urologist can then determine whether further evaluation or treatment is needed.
Don’t continue to wonder about what causes low testosterone in men – schedule an appointment today!