When you reach a certain age, your brain releases hormones that trigger the start of puberty — the time in life when a boy or girl becomes sexually mature. Meanwhile, sex hormones can help control the development of secondary sexual characteristics, such as testicles in men, breasts in women, and pubic hair growth in both sexes. 

In men, the sex hormone testosterone plays a significant role in sperm production, masculine growth, and development during puberty. It can also help regulate muscle mass, fat distribution, fertility, and red blood cell production. Unfortunately, testosterone deficiency is becoming more and more common, affecting around 4 to 5 million men in the United States. And studies suggest that low testosterone or hypogonadism is often underdiagnosed and undertreated.

There is a clear need to increase awareness of hypogonadism, especially among younger men and healthcare providers. Because not only does it reduces the quality of life, but it can also result in loss of livelihood and separation of couples, leading to divorce. 

Low testosterone is generally more common in men in their 50s and increases with age. But unlike menopause in women, testosterone deficiency is not an inevitable result of aging in men. This article outlines common evidence-backed factors that cause testosterone deficiency, particularly in men. 

What is Testosterone Deficiency (Hypogonadism)?

Testosterone is a primary sex hormone (androgen) in men made by the testicles and adrenal glands that are important for normal development and overall well-being. It is also made in a woman’s ovaries but in small amounts. 

When a man’s testicles do not produce sufficient testosterone (below 300 ng/dl), a condition called testosterone deficiency (or hypogonadism) occurs. This condition causes several symptoms, including low energy, poor concentration, low sex drive, erectile dysfunction, and depression. 

Types of Hypogonadism

There are two basic types of testosterone deficiency: primary and secondary hypogonadism. 

Primary hypogonadism

Primary hypogonadism typically occurs when you have underactive testes.  This condition limits the production of testosterone levels necessary for optimal growth and health. Some people have underactive testicles from genetic predispositions, while others acquire them from injuries or accidents.  

Secondary hypogonadism

Men with secondary hypogonadism, also known as hypogonadotropic hypogonadism, have normal testes. However, they don’t function properly due to issues with the hypothalamus or pituitary gland. Disorders affecting these parts of the brain can lead to altered testosterone production by the testes and insufficient testosterone levels in the blood. 

Risk Factors for Hypogonadism

People with testosterone deficiency have either primary or secondary hypogonadism. In some cases, they have a mixture of both. However, testosterone deficiency is not limited to inherited conditions or testicular injuries. Here are some common risk factors that contribute to lower testosterone production:

1. Age

Like in most things, age can impact how the body produces hormones like estrogen in women and testosterone in men. During the adolescent phase (age 10 to 19 years), testosterone levels tend to peak as it drives the physical changes men experience during puberty. 

However, as men age, there may be a gradual decline in both the testes and hypothalamic function. Aging diminishes testosterone production and reduces the hypothalamic secretion of gonadotropin-releasing hormone (GnRH). As a result, the pituitary gland does not secrete adequate luteinizing hormone (LH) to stimulate the testes to make testosterone. 

Here are the healthy testosterone levels for men by age:

• 0-5 months old: 75-400 ng/dl
• 6-9 years old: 7-20 ng/dl
• 10-11 years old: 7-130 ng/dl
• 12-13 years old: 7-800 ng/dl
• 14 years old: 7-1,200 ng/dl
• 15-16 years old: 100-1,200 ng/dl
• 17-18 years old: 300-1,200 ng/dl
• 19 years and older: 240 -950 ng/dl

Here are the prevalence rates of hypogonadism in men by age:

• Men in their 50s: 12%
• Men in their 60s: 19%
• Men in their 70s: 28%
• Men in their 80s: 49%

While evidence indicates that hypogonadism increases with age, older men who are healthy and are not overweight usually do not experience a significant drop in serum testosterone levels.

2. Genes

Your genetic makeup has a significant influence on how your body produces testosterone and how it functions. Although age can be a reference for how much testosterone is needed to be healthy, the ideal testosterone level still varies from person to person. At the same time, genetic abnormalities or conditions can cause testosterone deficiencies in men at any age.

Inherited conditions that decrease testosterone production include:

• Hemochromatosis: A medical condition in which too much iron builds up in the body, causing testicular failure or pituitary damage.

• Undescended testes: A genetic condition in which the testes do not move down into the scrotum, affecting normal function and may lead to infertility later in life.

• Klinefelter’s syndrome: A chromosomal condition in which a man is born with an extra X chromosome, affecting the development of testes.

• Kallman’s syndrome: An abnormal hypothalamus development that can lead to hypogonadism. About 60% of patients with idiopathic hypogonadotropic hypogonadism (IHH) are associated with this genetic condition. 

3. Health Conditions and Disease

In some cases, the drop in testosterone levels in the blood is due to diseases you acquire at one point in your life. Certain disease conditions can cause injury to the testes or affect the functions of the pituitary gland and hypothalamus. 

Here are some health conditions or diseases that can lower testosterone production:

• Inflammatory diseases (such as histiocytosis, sarcoidosis, and tuberculosis) can alter testosterone production. One study reported that 72% of patients with active tuberculosis also had hypogonadotropic hypogonadism (HH). 

• HIV/AIDS: A viral disease that can lower testosterone levels by affecting the pituitary, hypothalamus, and testes. Data suggests that HH is typical and occurs prematurely in HIV-infected men.

• Pituitary disorders you get from drugs, kidney failure, or small tumors can impair the release of hormones to the testes, causing testosterone deficiency.

• Physical injury to testicles: Injury to both testicles can lead to decreased testosterone production.

• Cancer treatment: Damaged testicles from chemotherapy or radiation can affect testosterone levels. Studies have shown that 30% of men with cancer experience hypogonadism. 

• Mumps orchitis: Infection from mumps can injure the testicles and lead to lower testosterone levels.

• Diabetes: Up to 40% of men with type 2 diabetes have hypogonadotropic hypogonadism. According to the American Diabetes Association, diabetic patients are twice as likely to suffer from low testosterone than men without diabetes.

4. Weight

Like diabetic patients, men having significant body fat at any age may alter hormone production and response. Obesity is often associated with hypogonadism, particularly concerning excess body fat and high plasma levels of leptin. It is the single most significant risk factor for testosterone deficiency, with male obesity secondary hypogonadism (MOSH) having a prevalence rate as high as 57.5%. 

Similarly, testosterone plays a significant role in carbohydrate, fat, and protein metabolism. Low serum testosterone can cause increased adipogenesis and visceral obesity, as evidenced by rapid weight gain in men following androgen deprivation therapy.

5. Sleep Quality

Your body naturally replenishes testosterone (and other hormones) while you sleep. And because testosterone production depends on quality sleep, this replenishment is most effective during REM sleep — the stage in which most people vividly dream. 

Research has confirmed a strong relationship between obstructive sleep apnea (OSA) and testosterone deficiency. OSA can constantly interrupt your sleep and reduce the amount of REM sleep you get at night. This constant poor sleep quality can hinder the replenishment cycle, which can lead to insufficient testosterone production. 

In one study, researchers restricted the sleep of 10 healthy young men to five hours per night. After one week, the results showed that their daytime testosterone levels decreased by 10% to 15%.

Related: Here’s another YHF article on insomnia and the consequences of poor sleep. 

6. Steroids

When a man is medically diagnosed with testosterone deficiency or hypogonadism, doctors usually prescribe testosterone replacement therapy (TRT) to return the testosterone level to normal. But while TRT is a safe medical treatment, using illegal steroids carries significant health risks, including cardiovascular disease, liver and brain damage, and hypogonadism.

For example, abusing steroids and opioids can alter the hypothalamic-pituitary-adrenal (HPA) axis, resulting in decreased testosterone secretion. Studies have shown that most people who misuse anabolic-androgenic steroids experience prolonged testosterone deficiency. 

7. Stress

Stress is known to cause a wide range of physical and mental health problems, including hypogonadism. According to a 2021 study, experiencing illness or surgery can trigger severe emotional or physical stress leading to problems with reproductive system functions. 

Another study suggests that hypogonadism and erectile dysfunction are associated with several environmental factors-induced oxidative stresses, such as exposure to pesticides, air pollution, radiation, and heavy metals.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                

Conclusion

Various factors can influence testosterone levels, and the cause of hypogonadism may vary from person to person. While aging, genetics, and certain inherited conditions are circumstances you can’t change, other factors, such as obesity, lack of sleep, steroid misuse, and stress, are more manageable and can be avoided.

With regular exercise, a healthy diet, and adequate rest, men can naturally boost their testosterone levels and help maintain energy and vitality even when they’re over 50. These lifestyle changes can also help revitalize marriages by improving the fertility and sex life of couples.  

For genetic conditions like undescended testes and Klinefelter’s syndrome, testosterone replacement therapy has proven effective and safe to use long-term. As long as men use it under proper guidelines, experts say it has minimal adverse effects and doesn’t increase the risk of prostate cancer. 

Ultimately, testosterone deficiency is manageable with a low risk of mortality. It is important to address potential risk factors before treatment. Nevertheless, patients and doctors tend to ignore the symptoms because they can easily be attributed to aging or other medical causes. And because hypogonadism can affect the quality of life, it is important to recognize that testosterone is not just a sex hormone but is also a vital part of health and well-being.