Understanding Low Testosterone Symptoms

Testosterone is an important hormone in a person’s overall health and well-being. Yet, millions of people suffer from low testosterone without being aware of it. This is known medically as male hypogonadism.

Although it is thought of as a condition specific to the male gender, testosterone plays an important role in women’s health as well, affecting libido, mood, muscle strength, and bone health.

Low testosterone can persist unnoticed for years because its symptoms are often attributed to stress, aging, or other medical issues. Early detection and proper diagnosis can help manage the condition effectively and improve long-term health outcomes.

Key Takeaways

• Low testosterone (low T) is a common but often underdiagnosed condition affecting both men and women, with symptoms like fatigue, low sex drive, depression, and reduced muscle mass.
• Testosterone levels are typically diagnosed through a morning blood test, and testosterone levels below 300 ng/dL are considered low for adult males.
• Causes of low testosterone include both primary (male hypogonadism) and secondary (pituitary gland or hypothalamus-related) hypogonadism, as well as lifestyle factors like obesity, sleep apnea, and medication use.
• Testosterone replacement therapy (TRT) is a common testosterone treatment and is available in several forms; however, it carries potential side effects like acne, sleep apnea, increased red blood cell count, and reduced fertility.
• Women with low testosterone may experience signs like chronic fatigue, mood swings, reduced sexual satisfaction, thinning hair, and weakened muscles, symptoms that are often overlooked or attributed to other conditions.

What Is Low Testosterone?

Low testosterone, often referred to as low T, is a condition in which the body doesn't produce enough testosterone, the primary male sex hormone. Testosterone is produced mainly in the testicles in men and in smaller amounts by the ovaries and adrenal glands in women. This hormone affects many bodily functions, and when testosterone levels fall below the actual range, a variety of symptoms can emerge. 

Low testosterone can also be referred to as:

1. Low T (non-medical shorthand often used in advertising and public awareness campaigns).
2. Testosterone Deficiency (medical term that describes low levels of testosterone without specifying the cause).
3. Testosterone Deficiency Syndrome (TDS) (a clinical term that emphasizes a broader set of symptoms and signs associated with chronically low testosterone levels).
4. Male Hypogonadism (Primary and secondary hypogonadism, sometimes called hypogonadotropic hypogonadism when associated specifically with pituitary or hypothalamic issues.)
5. Androgen Deficiency (Often used in the context of age-related testosterone decline, especially in older men, the full term sometimes used is "androgen deficiency in the aging male (ADAM)).

What Does Testosterone Do?

Testosterone helps maintain:

• Strength and mass in the muscle
• Bone density
• Erythrocyte count
• Sex drive (libido)
• Erectile function
• Sperm production
• Hair growth and body fat distribution
• Development of the male reproductive system during puberty

Testosterone also influences mood, cognitive function, and sleep patterns.

What Is a Low Testosterone Level?

A blood test is the primary tool used to diagnose low testosterone. The testosterone level range for older males is typically between 300 and 1,000 ng/dL.

Very low testosterone levels are below 300 ng/dL and are considered deficient.

However, testosterone levels vary slightly between labs and individuals, and long-term low testosterone readings may point to testosterone deficiency

Who Can Have Low Testosterone?

Low testosterone can affect:

• Adult males, especially as they age
• Women, though their normal levels are lower than those of men
• Children and adolescents with developmental issues

According to the American Urological Association, 2 out of 10 men over age 60 have low T, and the percentage increases with age.

What Causes Low Testosterone?

Low testosterone can stem from two broad categories:

• Primary hypogonadism (originating in the testes)
• Secondary hypogonadism (originating in the brain: pituitary gland or hypothalamus)
  Other contributing causes include:
  
  • Aging
  • Obesity
  • Sleep apnea
  • Chronic illnesses
  • Certain medications
  • Chemotherapy or radiation for prostate cancer

Certain medical conditions, such as a history of prostate cancer, can also lead to low testosterone.

Causes of Primary Male Hypogonadism

Primary causes that affect the testes directly include:

• Klinefelter syndrome (a genetic condition)
• Undescended testicles (occur when one or both testicles fail to descend into the scrotum before birth or within the first few months of life.)
• Mumps orchitis (testicular inflammation)
• Hemochromatosis (iron overload)
• Injury or radiation to the testicles

Causes of Secondary Male Hypogonadism

These involve the pituitary gland or hypothalamus, which control the testosterone production via hormones like luteinizing hormone (LH) and follicle-stimulating hormone (FSH):

• Pituitary gland tumors or problems
• Use of opioids, steroids, or chemotherapy
• Chronic illnesses like HIV/AIDS
• Obesity
• Sleep apnea

What Are the Symptoms of Low Testosterone?

The symptoms of low testosterone can be easily mistaken for other health issues.

These symptoms differ in males, females, and children. They include:

Low Sex Drive (Decreased Libido)

Testosterone plays a central role in regulating sexual desire in both men and women. When testosterone levels drop, individuals may notice:

• A diminished interest in sexual activity
• Fewer sexual thoughts or fantasies
• Reduced responsiveness to erotic stimuli

This loss of libido can affect relationships and may contribute to emotional distress or intimacy issues.

Erectile Dysfunction (ED)

While testosterone isn't the only factor involved in achieving and maintaining erections, it is necessary for:

• Stimulating receptors in the brain to trigger sexual arousal
• Supporting nitric oxide production, which helps blood flow to the penis

Low testosterone can make it more difficult to achieve firm erections, particularly spontaneous ones (e.g., morning erections). It may also reduce the effectiveness of ED medications.

Fatigue and Reduced Energy

Chronic fatigue is one of the most common complaints among men with testosterone deficiency. Symptoms include:

• Persistent tiredness despite adequate sleep
• Reduced motivation and drive
• Difficulty completing daily tasks or maintaining physical activity

This can significantly affect work performance, family life, and overall quality of life.

Decreased Muscle Mass and Strength

Testosterone is an anabolic hormone, meaning it supports muscle building. When testosterone levels are low, people may notice:

• Loss of muscle mass (especially in the arms, legs, and chest)
• Reduced physical strength 
• Slower recovery after workouts or physical exertion

Even with regular exercise, muscle growth may plateau or decline with low testosterone.

Increased Body Fat

Low testosterone often leads to an imbalance between fat storage and muscle development. This can result in:

• General weight gain
• Increased abdominal or visceral fat (connected to a higher risk of metabolic syndrome)
• In some cases, gynecomastia (enlarged breast tissue in men) due to hormonal imbalance

This shift in body composition can further reduce self-esteem and physical fitness.

Mood Swings, Depression, or Irritability

Testosterone has a direct effect on mood regulation and emotional stability. Low levels can contribute to:

• Depressive symptoms, including sadness and loss of interest
• Anxiety or irritability
• Decreased confidence and increased sensitivity to stress

Some men report feeling “flat” emotionally or disconnected from their usual personality.

Difficulty Concentrating and Memory Problems

Cognitive functions such as memory, focus, and verbal skills can be impaired by low testosterone. Individuals may notice:

• “Brain fog” or mental fatigue
• Shortened attention span
• Trouble organizing thoughts or recalling information

These symptoms can mimic early cognitive decline.

Decreased Bone Density

Testosterone helps maintain bone mineral density. Without adequate testosterone levels:

• Bones become thinner and weaker
• The risk of fractures increases, especially in the hips, spine, and wrists

In men, osteoporosis (a condition where bones become weakened and brittle, increasing the risk of fractures, particularly in the elderly) is often overlooked but can be a serious consequence of long-term testosterone deficiency.

Reduced Sperm Count and Infertility

In men, testosterone is essential for spermatogenesis (sperm production). Low testosterone levels can result in:

• Lower sperm volume
• Reduced fertility or complete infertility
• Smaller testicular size and changes in ejaculate

Men trying to conceive may require a fertility evaluation if testosterone deficiency is suspected.

Symptoms of Low Testosterone in Children

In boys, testosterone deficiency may lead to:

• Underdeveloped male genitals
• Lack of facial and body hair
• Delayed puberty
• Excessive growth of arms and legs due to delayed bone development

Symptoms of Low Testosterone in Males

• Reduced sex drive
• Erectile dysfunction
• Loss of muscle mass
• Increased fat accumulation
• Decreased energy and motivation
• Low libido
• Fatigue
• Reduced muscle strength
• Depression
• Infertility
• Loss of hair growth

Symptoms of Low Testosterone in Females

Women may also experience testosterone deficiency, although it presents differently:

• Chronic tiredness not relieved by rest
• Mood swings, irritability, or depression
• Decline in sexual satisfaction
• Loss of motivation and cognitive sharpness
• Weakened muscles and reduced exercise endurance
• Poor skin tone and hair texture
• Low sex drive
• Decreased bone density
• Reduced muscle tone
• Thinning hair
• Loss of mental focus
• Decreased sense of well-being

These symptoms are sometimes mistaken for general aging or other hormonal changes, such as menopause. However, testing and proper evaluation by a healthcare provider can reveal if testosterone deficiency is the root cause.

How Is Low Testosterone Diagnosed?

Diagnosis includes:

• Review of symptoms and medical history
• Physical exam
• Morning blood test to evaluate testosterone levels
• Repeat testing to confirm testosterone deficiency

Persistent symptoms and confirmed low testosterone levels may warrant testosterone therapy.

What Tests Will Be Done to Diagnose Low Testosterone?

• Total testosterone: Primary diagnostic test
• Free testosterone: In cases where sex hormone binding globulin (SHBG) is abnormal
• Luteinizing hormone (LH) and FSH: To determine if the issue is primary or secondary hypogonadism
• Prolactin and pituitary imaging if a pituitary gland problem is suspected

How Is Low Testosterone Treated?

Low testosterone can be treated with testosterone replacement therapy (TRT), which may come in several forms:

• Injectable testosterone
• Transdermal patches
• Gels and creams
• Oral testosterone (it is not commonly used due to liver effects)

Testosterone Therapy

Once diagnosed, testosterone treatment may be considered. The most common form is testosterone replacement therapy.

Testosterone replacement therapy is often used to manage symptoms in patients with testosterone deficiency.

What Are the Side Effects of Testosterone Replacement Therapy?

While testosterone replacement can significantly improve quality of life, it has potential risks, which include:

• Acne and oily skin
• Breast tissue enlargement (gynecomastia)
• Increased red blood cell count (risk of blood clots)
• Suppression of sperm production, potentially producing infertility
• Sleep apnea aggravation

Who Shouldn’t Undergo Testosterone Replacement Therapy?

Testosterone replacement therapy is not for everyone. It should be avoided or used with caution in men with:

• Prostate cancer or breast cancer
• Untreated sleep apnea
• High red blood cell count
• Low sperm count

Can Low Testosterone Be Prevented?

While some causes, like genetics, occur naturally, lifestyle factors can help improve testosterone production:

• Maintain a healthy weight
• Exercise regularly, especially strength training
• Get adequate sleep
• Avoid excessive alcohol and opioid use
• Manage chronic conditions like diabetes

When Should I See My Healthcare Provider About Low Testosterone?

See your healthcare provider if you experience:

• Persistent fatigue
• Erectile dysfunction
• Loss of sex drive
• Noticeable changes in muscle strength, mood, or cognitive function

Final Thoughts

Low testosterone is real, and if you're experiencing symptoms of it, a blood test and consultation with a healthcare provider can confirm the diagnosis. Fortunately, with testosterone replacement therapy, many people can regain their energy, strength, and vitality.

References

1. American Urological Association. Evaluation and Management of Testosterone Deficiency. 2018.
2. Mayo Clinic Staff. Low Testosterone (Male Hypogonadism). Mayo Clinic. 2023.
3. Harvard Health Publishing. Testosterone therapy: Potential benefits and risks as you age.
4. Endocrine Society Clinical Practice Guideline. Testosterone Therapy in Men with Hypogonadism. 2018.
5. Journal of Clinical Endocrinology & Metabolism. Testosterone treatment and risk of venous thromboembolism. 2019.
6. Cleveland Clinic. Low Testosterone (Male Hypogonadism). Updated 2022.