Low Testosterone (Male Hypogonadism)

What is low testosterone (male hypogonadism)?

Low testosterone (male hypogonadism) is a condition in which your testicles don’t produce enough testosterone (the male sex hormone). More specifically, the Leydig cells in your testicles make testosterone.

Low testosterone causes different symptoms at different ages. Testosterone levels in adults naturally decline with age.

Other names for low testosterone and male hypogonadism include:

• Testosterone deficiency syndrome.
• Testosterone deficiency.
• Primary hypogonadism.
• Secondary hypogonadism.
• Hypergonadotropic hypogonadism.
• Hypogonadotropic hypogonadism.

What does testosterone do?

Testosterone is the main androgen. It stimulates the development of male characteristics and is essential for sperm production (spermatogenesis). Levels of testosterone are naturally much higher in men than women.

In men, testosterone helps maintain and develop:

• Sex organs and genitalia.
• Muscle mass.
• Adequate levels of red blood cells.
• Bone density.
• Sense of well-being.
• Sexual and reproductive function.

Your body usually tightly controls the levels of testosterone in your blood. Levels are typically highest in the morning and decline through the day.

Your hypothalamus and pituitary gland normally control the amount of testosterone your testicles produce and release.

Your hypothalamus releases gonadotropin-releasing hormone (GnRH), which triggers your pituitary gland to release luteinizing hormone (LH). LH then travels to your gonads (testicles or ovaries) and stimulates the production and release of testosterone. Your pituitary also releases follicle-stimulating hormone (FSH) to cause sperm production.

Any issue with your testicles, hypothalamus or pituitary gland can cause low testosterone (male hypogonadism).

What is a low testosterone level?

The American Urology Association (AUA) considers low blood testosterone to be less than 300 nanograms per deciliter (ng/dL) for adults.

However, some researchers and healthcare providers disagree with this and feel that levels below 250 ng/dL are low. Providers also take symptoms into consideration when diagnosing low testosterone.

Who does low testosterone (male hypogonadism) affect?

Male hypogonadism is a medical condition that can affect people with testicles at any age from birth through adulthood.

Low testosterone is more likely to affect people who:

• Are older.
• Have obesity.
• Have poorly managed Type 2 diabetes.
• Have obstructive sleep apnea.
• Have chronic medical conditions, such as kidney dysfunction or cirrhosis of the liver.
• Have HIV/AIDs.

How common is low testosterone?

It’s difficult for researchers to estimate how common low testosterone is since different studies have different definitions for low testosterone.

Data suggest that about 2% of men may have low testosterone. And other studies have estimated that more than 8% of men aged 50 to 79 years have low testosterone.

What are the symptoms of low testosterone?

Symptoms of low testosterone can vary considerably, particularly by age.

Symptoms that highly suggest low testosterone in men include:

• Reduced sex drive.
• Erectile dysfunction.
• Loss of armpit and pubic hair.
• Shrinking testicles.
• Hot flashes.
• Low or zero sperm count (azoospermia), which causes male infertility.

Other symptoms of low testosterone in men include:

• Depressed mood.
• Difficulties with concentration and memory.
• Increased body fat.
• Enlarged male breast tissue (gynecomastia).
• Decrease in muscle strength and mass.
• Decrease in endurance.

Symptoms of low testosterone in children

Low testosterone before or during puberty for boys:

• Slowed growth in height, but their arms and legs may continue to grow out of proportion with the rest of their body.
• Reduced development of pubic hair.
• Reduced growth of their penis and testicles.
• Less voice deepening.
• Lower-than-normal strength and endurance.

What causes low testosterone?

There are several possible causes of low testosterone. The two types of male hypogonadism are:

• Primary hypogonadism (testicular disorder).
• Secondary hypogonadism (pituitary/hypothalamus dysfunction).

Causes of primary and secondary hypogonadism are also divided into either congenital (at birth) or acquired (developed later in childhood or adulthood).

Causes of primary male hypogonadism

Primary hypogonadism happens when something is wrong with your testicles that doesn’t allow them to make normal levels of testosterone.

Another name for primary hypogonadism is hypergonadotropic hypogonadism. In this type, your pituitary gland produces more luteinizing hormone (LH) and follicle-stimulating hormone (FSH) (known as gonadotropins) in response to low testosterone levels. The high levels of these hormones would normally tell your testicles to produce more testosterone and sperm. However, if you have damaged (most commonly related to prior chemotherapy) or missing testicles, they can’t respond to the increased levels of gonadotropins. As a result, your testicles make too little or no testosterone and sperm.

Sometimes in primary hypogonadism testosterone levels are within the normal range and gonadotropins are high. Your specialist will help you understand if you need treatment, even with normal testosterone levels.

Congenital conditions that affect your testicles and can lead to primary hypogonadism include:

• Absence of testicles at birth (anorchia).
• Undescended testicles (cryptorchidism).
• Leydig cell hypoplasia (underdevelopment of Leydig cells in your testicles).
• Klinefelter’s syndrome (a genetic condition in which males are born with an extra X chromosome: XXY instead of XY).
• Noonan syndrome (a rare genetic condition that can cause delayed puberty, undescended testicles or infertility).
• Myotonic dystrophy (part of a group of inherited disorders called muscular dystrophies).

Acquired conditions that affect your testicles and can lead to primary hypogonadism include:

• Testicle injury or removal.
• Orchitis, which is inflammation of one or both testicles. This is most often the result of a bacterial infection, such as a sexually transmitted infection, but it can be due to viral infections, such as mumps.
• Chemotherapy or radiation therapy to your testicles.
• Certain types of tumors.
• Anabolic steroid use.

Causes of secondary male hypogonadism

Conditions that affect how your hypothalamus and/or pituitary gland cause secondary hypogonadism. This is known as hypogonadotropic hypogonadism because there are low levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Those low levels cause decreased testosterone and sperm production.

Congenital conditions that can lead to secondary hypogonadism include:

• Isolated hypogonadotropic hypogonadism (a condition that causes low levels of gonadotropin-releasing hormone from birth).
• Kallmann syndrome (a rare genetic condition that causes loss of the development of nerve cells in your hypothalamus that produce gonadotrophin-releasing hormone. It can also cause a lack of smell.).
• Prader-Willi syndrome (a rare genetic multisystem disorder than can cause hypothalamus dysfunction).

Acquired conditions that can lead to secondary hypogonadism include:

• Hypopituitarism (This condition may result from an adenoma, infiltrative disease, infection, injury, radiation therapy or surgery that affects your pituitary gland.).
• Hyperprolactinemia.
• Iron overload (hemochromatosis).
• Brain or head injury.
• Cushing’s syndrome.
• Cirrhosis of the liver.
• Kidney failure.
• HIV/AIDS.
• Alcohol use disorder.
• Poorly managed diabetes.
• Obesity.
• Obstructive sleep apnea.
• Certain medications, including estrogens, psychoactive drugs, metoclopramide, opioids, leuprolide, goserelin, triptorelin and newer androgen biosynthesis inhibitors for prostate cancer.

Late-onset hypogonadism (LOH) is a type of secondary male hypogonadism that results from normal aging. As males age they have a deterioration of hypothalamic-pituitary function and Leydig cell function that decrease testosterone and/or sperm production.

LOH and low testosterone are more common in men who have Type 2 diabetes, overweight and/or obesity.

In one study, 30% of men who were overweight had low testosterone, compared to only 6% of those with weight in the normal range. In another study, 25% of men with Type 2 diabetes had low testosterone, compared to 13% of those without diabetes.

How is low testosterone diagnosed?

If you have signs and symptoms of low testosterone, a healthcare provider will perform a physical exam. They’ll also ask questions about your medical history, medications you take or have taken, smoking history and any symptoms you currently have. Blood tests may be ordered.

To make a diagnosis, a provider will consider your specific signs, symptoms and any blood test results.

What tests will be done to diagnose low testosterone?

The following tests can help confirm low testosterone and determine the cause:

• Total testosterone level blood test: This test usually requires two sample collections between 8 a.m. and 10 a.m., when testosterone levels should be at their highest. If you’re sick or have recently been sick, it’s important to tell your provider. Acute illness may cause a falsely low result.
• Luteinizing hormone (LH) blood test: This test can help determine if the cause of low testosterone is an issue with your pituitary gland.
• Prolactin blood test: High prolactin levels may be a sign of pituitary gland issues or tumors.

How is low testosterone treated?

Healthcare providers treat low testosterone (male hypogonadism) with testosterone replacement therapy. Testosterone replacement therapy has several different forms, including:

• Testosterone skin gels: You apply the gel every day to clean, dry skin as directed. It’s important that you don’t transfer the gel to another person through skin-to-skin contact. Testosterone skin gels are one of the most common forms of treatment in the U.S.
• Intramuscular testosterone injections: You or a provider can administer the injections into a muscle every 1 to 2 weeks. Providers can administer long-acting testosterone by injection every 10 weeks. There are also subcutaneous injection options.
• Testosterone patches: You apply these patches every day to your skin as directed. You usually have to rotate their location to avoid skin reactions.
• Testosterone pellets: A specialist implants these pellets under your skin every three to six months. The pellets provide consistent and long-term testosterone dosages.
• Buccal testosterone tablets: These are sticky pills that you apply to your gums twice a day. The testosterone absorbs quickly into your bloodstream through your gums.
• Testosterone nasal gel: You apply a testosterone gel by applying it into each nostril three times a day.
• Oral testosterone: A pill form of testosterone called undecanoate is available for people with low testosterone due to specific medical conditions, such as Klinefelter syndrome or tumors that have damaged their pituitary gland.

You may not be able to receive testosterone replacement therapy if you have a history of the following:

• Prostate cancer.
• An unevaluated lump on your prostate. Everyone considering testosterone replacement therapy must undergo prostate screening before starting this therapy.
• Breast cancer.
• Uncontrolled heart failure.
• Untreated obstructive sleep apnea.

What are the side effects of testosterone replacement therapy?

The side effects of testosterone replacement therapy include:

• Acne or oily skin.
• Swelling in your ankles caused by mild fluid retention.
• Stimulation of the prostate, which can cause urinary symptoms such as difficulty peeing.
• Breast enlargement or tenderness.
• Worsening of sleep apnea.
• Smaller testicles.
• Skin irritation (if you use topical testosterone replacement).

Laboratory abnormalities that can occur with testosterone replacement therapy include:

• Increase in prostate-specific antigen (PSA).
• Increase in red blood cell count.
• Decrease in sperm count, producing infertility (inability to have children), which is especially important in younger people who want to have biological children.

What can I expect if I have low testosterone (male hypogonadism)?

There’s no one-time fix for low testosterone. However, consistent hormone replacement therapy helps improve sex drive, ease symptoms of depression and increase energy levels for those experiencing low testosterone. Treatment may also boost muscle mass and bone density.

The mortality of men with testosterone deficiency is significantly higher than among men with normal testosterone levels. But, it is unclear whether replacing testosterone to a normal level reduces that increased mortality. Treatment is largely focused on the treatment of symptoms, not the specific testosterone level.

For congenital hypogonadism, testosterone replacement therapy often helps prevent problems related to delayed puberty.

Can low testosterone be prevented?

Healthcare providers and medical researchers don’t know how to prevent low testosterone from genetic conditions or damage to your testicles, hypothalamus or pituitary gland.

Lifestyle habits that may help keep testosterone levels normal include:

• Eating a healthy diet.
• Exercise.
• Weight management.
• Avoiding excessive use of alcohol and drugs.

When should I see my healthcare provider about low testosterone?

If you’re taking hormone replacement therapy, regular follow-up appointments with a healthcare provider are important.

If you’re experiencing symptoms of low testosterone, such as a decrease in sex drive and hot flashes, talk to a healthcare provider. They will evaluate you and may order blood tests.

If your child isn’t showing signs of puberty by the age of 14, talk to their pediatrician.