Hormonal imbalance in men most often involves testosterone levels that are too low, estrogen levels that are too high, or both at once. The causes range from natural aging and weight gain to medical conditions affecting the brain or testes. Understanding what drives these shifts can help you recognize patterns in your own health and have a more productive conversation with your doctor.
How Male Hormones Are Regulated
Your hormone system runs on a feedback loop between your brain and your testes. The hypothalamus, a small region at the base of the brain, releases a signaling hormone that tells the pituitary gland to produce two messenger hormones. These messengers travel through the bloodstream and tell the testes to produce testosterone. When testosterone levels are adequate, the brain dials back its signals. When they drop, the brain ramps up production.
A problem anywhere in this chain can throw things off. Doctors generally classify the cause as either primary (the testes themselves aren’t working properly) or secondary (the brain’s signaling centers aren’t functioning correctly). Some causes are present from birth, while others develop later from injury, illness, or lifestyle factors.
Primary Causes: Problems in the Testes
When the testes can’t produce enough testosterone despite receiving the right signals from the brain, the issue is called primary hypogonadism. The most common genetic cause is Klinefelter syndrome, a condition present from birth in which a man carries an extra X chromosome. This affects testicular development and often isn’t diagnosed until puberty or adulthood, when symptoms like low energy, reduced muscle mass, or fertility problems become apparent.
Other causes of primary testicular failure include:
- Physical injury or trauma to the testes
- Infections that damage testicular tissue (mumps being a classic example)
- Radiation or chemotherapy targeting the groin area
- Surgery involving the testes
- Iron overload (hemochromatosis), which can deposit iron in testicular tissue
- Liver or kidney disease, which disrupts how the body processes hormones
- Autoimmune disorders in which the immune system attacks the testes
Secondary Causes: Problems in the Brain
Secondary hypogonadism occurs when the hypothalamus or pituitary gland fails to send the right signals. Pituitary tumors, including noncancerous growths called prolactinomas, are a well-known cause. These tumors can press on surrounding tissue and disrupt the release of the messenger hormones that stimulate testosterone production.
Head trauma, brain surgery near the pituitary, and radiation to the head or neck can also damage these signaling centers. So can certain genetic conditions. Kallmann syndrome, for instance, impairs the hypothalamus and typically causes delayed or absent puberty along with a reduced sense of smell.
Medications are another significant trigger. Opioid painkillers and glucocorticoids (prescribed for inflammation and autoimmune conditions) can suppress the brain’s hormonal signals. Anabolic steroid use is particularly disruptive: while steroids flood the body with synthetic testosterone, they simultaneously shut down the brain’s natural signaling loop. When a man stops taking them, the brain’s ability to restart production can take months or even fail to fully recover.
How Body Fat Alters Hormone Balance
Excess body fat is one of the most common and underappreciated causes of hormonal imbalance in men. Fat tissue contains an enzyme called aromatase that converts testosterone into estrogen. The more fat you carry, the more active this conversion becomes. The result is a double hit: testosterone drops while estrogen rises.
This creates a self-reinforcing cycle. Lower testosterone makes it harder to build muscle and easier to gain fat. More fat means more aromatase activity, which drives testosterone even lower and estrogen higher. Men caught in this loop often notice symptoms from both sides of the imbalance: fatigue, reduced sex drive, and difficulty losing weight from the low testosterone, plus breast tissue swelling and erectile dysfunction from the elevated estrogen.
Rapid, significant weight loss can also disrupt hormones, though in a different way. Severe calorie restriction or weight loss after bariatric surgery can temporarily suppress the brain’s hormonal signaling, leading to a period of low testosterone until the body stabilizes.
Chronic Stress and Cortisol
Your body’s stress response and reproductive hormones work against each other by design. When you’re under sustained stress, your adrenal glands produce high levels of cortisol, the body’s primary stress hormone. Chronically elevated cortisol directly inhibits testosterone production and can cause reduced sex drive and erectile difficulties.
Research on overtrained athletes illustrates this relationship clearly. In one study, men who were pushed into an overtraining state saw their testosterone drop from an average of 8.68 ng/mL to 5.37 ng/mL, while their cortisol climbed from 145.7 ng/mL to 215.3 ng/mL. The inverse relationship between the two hormones was extremely strong statistically. The good news: both hormones returned to normal within three months once training volume was reduced.
This pattern isn’t limited to athletes. Any source of chronic stress, whether physical, psychological, or from sleep deprivation, can tip the cortisol-testosterone balance. Poor sleep is particularly potent because testosterone production peaks during deep sleep. Consistently cutting sleep short reduces the body’s primary window for hormone production.
Environmental Chemical Exposure
Certain synthetic chemicals interfere with the body’s hormone system. Known as endocrine disruptors, these substances can block, mimic, or alter hormone signaling. Phthalates are among the most studied. Found in plastics, personal care products, and fragranced household items, phthalates directly interfere with testosterone production. They’re so widespread that most people carry measurable levels in their bodies.
Other common endocrine disruptors include pesticides, industrial solvents, and compounds found in food packaging. While a single exposure is unlikely to cause noticeable hormonal changes, long-term, low-level exposure from multiple sources adds up over time. Reducing contact with these chemicals, choosing fragrance-free products, avoiding heating food in plastic containers, filtering drinking water, is a practical step you can take, though it won’t reverse imbalances caused by other factors.
Age-Related Decline
Testosterone naturally decreases as men age, typically dropping by about 1 to 2 percent per year after age 30. This gradual decline is normal and doesn’t automatically qualify as a hormonal disorder. Many men maintain testosterone well within the healthy range throughout their lives. Others, especially those with additional risk factors like obesity, chronic illness, or medication use, may drop below the threshold where symptoms appear.
The American Urological Association considers a total testosterone level below 300 ng/dL a reasonable cutoff for diagnosing low testosterone. For reference, the normal adult male range is roughly 193 to 824 ng/dL, though labs vary slightly in their reference ranges. Diagnosis requires two separate blood draws, both taken in the early morning when testosterone peaks, along with the presence of actual symptoms. A low number on a lab report alone isn’t enough.
Recognizing the Signs
Hormonal imbalance in men doesn’t always look the same because the symptoms depend on which hormones are off and in which direction. Low testosterone commonly causes fatigue, reduced muscle mass, increased body fat (especially around the midsection), low sex drive, depressed mood, and difficulty concentrating. Some men also notice thinning body hair or a decrease in bone density over time.
When estrogen is elevated relative to testosterone, additional symptoms can appear: breast tissue swelling or tenderness, erectile dysfunction, and in some cases, infertility or an increased frequency of migraines. Men with low estrogen, which is less commonly discussed, may experience bone loss and excess belly fat.
Because many of these symptoms overlap with other conditions like depression, thyroid disorders, or simple sleep deprivation, blood testing is the only reliable way to confirm a hormonal cause. If you’re experiencing several of these symptoms together, particularly reduced sex drive combined with fatigue and body composition changes, hormone levels are worth checking.