How Low Testosterone Affects the Body: Signs, Symptoms, and Management

Comprehensive guide to understanding, recognizing, and managing the many ways low testosterone can affect physical and emotional health.

By Sneha Tete, Integrated MA, Certified Relationship Coach

Created on Sep 26, 2025

Comprehensive guide to understanding, recognizing, and managing the many ways low testosterone can affect physical and emotional health.

Testosterone is a vital hormone in the human body, responsible for a range of physiological functions in both males and females. It’s best known for its role in male sexual development, but its influence spans mood, energy, body composition, and more. When testosterone levels dip below normal—a condition also known as male hypogonadism—the effects can be widespread and significantly impact quality of life. This article explores the various ways low testosterone can affect your body, what symptoms to look out for, other potential causes, and how to manage these changes.

Understanding Testosterone and Its Role

Testosterone is the principal sex hormone in males, produced mainly in the testicles and, to a smaller extent, in the adrenal glands and ovaries (in females). It begins rising significantly during puberty and plays a key role in developing secondary sex characteristics, such as increased muscle mass, body hair, deepening voice, and sperm production. While often associated with men, testosterone is present—and essential—in everyone.

After the age of 30, testosterone levels in males naturally decline at a gradual rate, typically 1% per year. However, a significant drop can lead to noticeable clinical symptoms and health effects.

Sexual Function

Testosterone is critically involved in sexual motivation and performance. With low levels, one may experience:

Decreased libido: Loss of sexual desire is one of the most common signs. Older adults may expect some reduction, but a marked decrease may indicate low testosterone.
Erectile difficulties: Testosterone helps initiate and maintain erections by signaling the brain to produce nitric oxide. Low levels can result in trouble achieving or sustaining erections or a decline in spontaneous erections (such as at night or in the morning).
Decreased ejaculation volume and sperm count: Reduced testosterone may affect fertility by impacting sperm production.
Infertility: Chronic low testosterone can be a cause of male infertility.

It is essential to note that erectile dysfunction can also be caused by other health conditions such as cardiovascular disease, diabetes, thyroid disorders, depression, or lifestyle factors like alcohol, smoking, and stress.

Physical Changes

Testosterone is fundamental for maintaining normal muscle mass, bone density, fat distribution, and the development of secondary sexual characteristics. When levels fall below normal, changes may include:

Decreased muscle mass and strength: Muscle mass may diminish with low testosterone, although the impact on muscle strength can vary.
Increased body fat: Low testosterone is linked to increases in body fat and changes in fat distribution, including the possible development of gynecomastia (enlarged male breast tissue).
Decreased bone density: Testosterone helps produce and strengthen bone. Its deficiency raises the risk of osteoporosis and bone fractures.
Hair loss: While male pattern baldness can be hereditary, low testosterone can result in loss of facial, body, and pubic hair.
Hot flashes: Some people experience sudden sensations of warmth, excessive sweating, and reddening of the skin, similar to menopausal hot flashes.
Changes in testicle and penis size: Prolonged low testosterone levels can result in a decrease in testicle volume and, less commonly, penile size.
Swelling or tenderness in breast tissue: Hormonal imbalances may lead to breast tissue changes in males.
Low blood counts (anemia): Chronic low testosterone has been associated with increased risk of anemia, characterized by low red blood cell counts.

Physical Changes Table

System/Area	Effect of Low Testosterone
Muscle Mass	Decreased size, possible loss of strength
Body Fat	Increase in overall fat, gynecomastia
Bone Density	Decreased, higher osteoporosis risk
Hair	Loss of body and facial hair
Reproductive Organs	Shrinking of testicles, possible reduction in penis size
Blood cells	Low red blood cell count (anemia)

Emotional and Cognitive Changes

Low testosterone isn’t only a physical issue—it can affect mental and emotional well-being as well. People may notice:

Depressed mood: Persistent feelings of sadness, anxiety, or irritability are common and may progress to clinical depression in some cases.
Decreased self-confidence: Individuals may experience lowered self-esteem and motivation.
Mood swings and emotional instability: Increased stress, irritability, and dissatisfaction with life may occur.
Difficulty with concentration and memory: Cognitive symptoms such as trouble remembering things or focusing can emerge, particularly as people age.

These symptoms can be made worse by other effects of low testosterone like fatigue, reduced libido, and sleep disturbances.

Sleep Disturbances and Fatigue

Fatigue is a well-known symptom of low testosterone. You may experience ongoing tiredness, difficulty backing sleep, or even insomnia.

Persistent fatigue: Feeling worn out despite adequate sleep is commonly reported.
Sleep disturbances: These may include difficulty falling or staying asleep and changes in sleep patterns.
Sleep apnea: Testosterone replacement therapy can sometimes increase the risk of sleep apnea, a condition where breathing frequently stops and starts during sleep. Notably, untreated sleep apnea itself can lower testosterone levels.
Night sweats: Sometimes linked to hot flashes, excessive sweating during the night might disrupt rest.

Other Effects and Warning Signs

Testosterone deficiency can result from various factors aside from natural aging:

Genetic and congenital conditions
Injuries or trauma to the testicles
Testicular cancer or treatments such as chemotherapy or irradiation
Infections affecting the hypothalamus, pituitary gland, or testicles
Chronic diseases, such as HIV or type 2 diabetes
Drug and alcohol use
Side effects of medications, especially those affecting hormones
Thyroid disorders

Various symptoms could overlap with other conditions or age-related changes. It’s crucial to consult a healthcare provider for diagnosis if any symptoms persist or impact your daily life.

What Causes Low Testosterone?

The causes of low testosterone include both primary hypogonadism (direct issues with the testicles) and secondary hypogonadism (problems with hormone signaling from the brain via the hypothalamus or pituitary gland). Other risk factors and contributors include:

Aging (after age 30, gradual decline)
Obesity and metabolic syndrome
Genetic disorders (e.g., Klinefelter syndrome)
Chronic illnesses (e.g., kidney or liver disease)
Cancer treatments (chemotherapy or radiation)
Infections such as mumps (if affecting the testicles)

Diagnosing Low Testosterone

Diagnosis typically includes a review of symptoms and medical history, blood tests measuring total and sometimes free testosterone, and ruling out other conditions. A diagnosis of low testosterone is often made if blood testosterone concentrations are consistently below the reference range and accompanied by clinical symptoms.

Treatment and Management

Management strategies vary by cause, severity, and overall health. Options include:

Testosterone replacement therapy (TRT): Administered via injections, gels, patches, or pellets. TRT is effective in raising testosterone levels but may not be suitable for everyone and can have side effects, such as raising the risk of blood clots or affecting prostate health.
Treating underlying conditions: Addressing primary causes such as weight loss, managing chronic illness, or switching medications if possible.
Lifestyle changes: Regular exercise, healthy diet, adequate sleep, and limiting alcohol can help minimize symptoms and improve overall well-being.
Monitoring and managing complications: Bone density scans, cholesterol management, and psychological support may be necessary for long-term health.

It is important to seek guidance from a healthcare provider before beginning any treatment, especially hormone therapy.

Frequently Asked Questions (FAQs)

What is considered a low testosterone level?
Most labs consider total testosterone levels below 300 ng/dL in adult males to be low, but clinical symptoms and individual reference ranges are important for diagnosis.
Are symptoms of low testosterone permanent?
Many symptoms can improve with treatment or lifestyle modification, though underlying causes may affect reversibility.
Does low testosterone only affect men?
No. While men are more commonly affected, women can also have symptoms of testosterone deficiency—though their normal levels are much lower.
Can low testosterone cause infertility?
Yes, testosterone is essential for sperm production. Prolonged deficiency can reduce fertility, but treatment may help reverse this effect.
How is low testosterone treated?
Doctors may recommend testosterone replacement therapy, lifestyle changes, weight loss, or treating any underlying illness contributing to low levels.
Is testosterone therapy safe for everyone?
No. People with a history of prostate or certain types of breast cancer and those prone to specific cardiovascular conditions may not be candidates for TRT.

References

Healthline Editorial Team. “Signs and Symptoms of Low Testosterone.” Healthline, 2025.
Block, A. R., MD MPH et al. “Common Side Effects of Low Testosterone in Men.” Healthline, 2025.
Healthline Video. “5 Symptoms of Low Testosterone (Low T).” Healthline, 2022.

References

Author

Sneha TeteBeauty & Lifestyle Writer

Sneha is a relationships and lifestyle writer with a strong foundation in applied linguistics and certified training in relationship coaching. She brings over five years of writing experience to thebridalbox, crafting thoughtful, research-driven content that empowers readers to build healthier relationships, boost emotional well-being, and embrace holistic living.

Read full bio of Sneha Tete