Low Testosterone in Men: Symptoms, Causes, Diagnosis & Treatment
Testosterone is an important hormone that plays a major role in male sexual health, muscle development, bone strength, energy, mood, and fertility.
Testosterone levels naturally decrease as men get older. However, when testosterone levels become too low and are accompanied by symptoms, this may be a condition known as male hypogonadism or testosterone deficiency.
At DokterForYou, we help men understand the possible causes of low testosterone and explore medically appropriate treatment options based on their symptoms, medical history, and hormone levels.
What Is Low Testosterone?
Testosterone is primarily produced by specialized cells called Leydig cells in the testicles.
Although testosterone is often considered the main male sex hormone, it is also produced in smaller amounts by the ovaries and adrenal glands.
Testosterone helps support:
Sexual development and function
Sex drive and fertility
Muscle mass and strength
Bone strength
Red blood cell production
Energy levels
Mood and overall well-being
Testosterone levels naturally decline with age. In some men, this decline can become significant enough to cause noticeable symptoms.
Low testosterone is also known as:
Testosterone deficiency
Low T
Male hypogonadism
Primary hypogonadism
Secondary hypogonadism
Late-onset hypogonadism
How Does Testosterone Change With Age?
Testosterone levels naturally decrease as men age.
Levels may begin to decline by approximately 1% per year from the late 30s or early 40s. However, not every man with lower testosterone will develop symptoms or require treatment.
A diagnosis generally requires both symptoms and consistently low testosterone levels, rather than relying on age or a single symptom alone.
Symptoms of Low Testosterone
Symptoms can vary significantly from one person to another.
Sexual Symptoms
Sexual symptoms are among the more specific signs associated with low testosterone.
They may include:
Reduced sex drive
Fewer morning or spontaneous erections
Difficulty achieving or maintaining an erection
Reduced fertility
Low sperm production
Other Symptoms
Low testosterone may also be associated with:
Low energy
Fatigue
Reduced muscle mass
Reduced muscle strength
Increased body fat
Low mood
Difficulty concentrating
Memory problems
Reduced physical endurance
Breast enlargement
Loss of armpit or pubic hair
Smaller testicles
Hot flashes
The presence of these symptoms does not automatically mean testosterone is low. Other medical conditions can cause similar symptoms, which is why proper medical evaluation is important.
Low Testosterone Before or During Puberty
When testosterone levels are low before or during puberty, boys may experience differences in normal development.
Possible signs include:
Slower growth in height
Reduced development of pubic hair
Smaller penis and testicles
Less deepening of the voice
Reduced muscle development
Lower strength and endurance
What Causes Low Testosterone?
Testosterone production is controlled through communication between the hypothalamus, pituitary gland, and testicles.
Problems affecting any part of this system can reduce testosterone production.
There are two main forms of male hypogonadism.
Primary Hypogonadism
Primary hypogonadism occurs when the problem originates in the testicles.
The testicles may not produce enough testosterone or sperm even when they receive normal hormonal signals from the brain.
Possible causes include:
Testicular injury
Removal of the testicles
Undescended testicles
Absence of testicles at birth
Klinefelter syndrome
Noonan syndrome
Leydig cell abnormalities
Testicular infections
Chemotherapy or radiation therapy
Certain tumors
Iron overload
Sarcoidosis
Secondary Hypogonadism
Secondary hypogonadism occurs when the problem affects the hypothalamus or pituitary gland, which normally regulate testosterone production.
Possible causes include:
Obesity
Type 2 diabetes
Pituitary disorders
High prolactin levels
Brain or head injuries
Cushing syndrome
Liver disease
Kidney failure
HIV/AIDS
Alcohol use disorder
Anabolic steroid use
Obstructive sleep apnea
Opioid use
Certain medications
Late-onset hypogonadism is another form of secondary hypogonadism and is more commonly seen in men with conditions such as obesity and Type 2 diabetes.
Risk Factors for Low Testosterone
Low testosterone may be more likely in men who:
Are over 45
Have overweight or obesity
Have poorly controlled Type 2 diabetes
Have obstructive sleep apnea
Have chronic medical conditions
Have kidney or liver problems
Have HIV/AIDS
Use anabolic steroids or certain medications
How Is Low Testosterone Diagnosed?
A doctor will usually begin with a medical history and physical examination.
Blood tests may then be used to confirm testosterone deficiency and investigate the possible cause.
Tests may include:
Total testosterone blood test
Hemoglobin
Hematocrit
Luteinizing hormone (LH)
Prostate-specific antigen (PSA)
Prolactin
Liver function tests
Testosterone levels can vary throughout the day, so doctors may recommend appropriate timing and repeat testing when necessary.
A diagnosis should be based on the combination of symptoms, laboratory results, and medical history.
Treatment for Low Testosterone
Treatment depends on the underlying cause, severity of symptoms, testosterone levels, age, fertility goals, and overall health.
Lifestyle Changes
Healthy lifestyle habits can support overall hormonal and metabolic health.
Important measures include:
Eating a nutritious, balanced diet
Maintaining a healthy weight
Exercising regularly
Getting adequate sleep
Managing stress
Limiting excessive alcohol consumption
Avoiding smoking
Managing conditions such as diabetes and obesity
For some men, addressing underlying health and lifestyle factors may improve testosterone levels and symptoms.
Testosterone Replacement Therapy (TRT)
For men with confirmed testosterone deficiency caused by male hypogonadism, a doctor may consider testosterone replacement therapy (TRT).
TRT provides manufactured testosterone to help restore hormone levels.
Treatment may be available in several forms, including:
Testosterone Gels
Testosterone can be applied to the skin in gel form.
Examples include testosterone skin gels such as Androgel.
Testosterone Injections
Testosterone can also be administered by injection at intervals determined by a healthcare professional.
Testosterone Pellets
Small testosterone pellets may be placed under the skin and release testosterone gradually.
Testosterone Nasal Gel
Some testosterone treatments are administered through the nose.
Oral Testosterone
Oral testosterone formulations may also be available depending on the patient's medical situation and local treatment options.
How Long Does TRT Take to Work?
The response to testosterone replacement therapy varies between individuals.
Some men may begin noticing changes in energy, mood, sexual function, or other symptoms after several weeks, while other improvements may take longer.
Regular medical monitoring is important to evaluate whether treatment is providing meaningful benefits and whether adjustments are necessary.
Possible Side Effects of TRT
Testosterone replacement therapy can cause side effects and is not appropriate for everyone.
Possible effects include:
Acne or oily skin
Fluid retention and ankle swelling
Breast enlargement or tenderness
Worsening of sleep apnea
Smaller testicles
Increased red blood cell count
Increased PSA levels
Urinary symptoms related to prostate stimulation
Reduced sperm production
Infertility
Because TRT can affect sperm production, men who are planning to have children should discuss fertility goals with their doctor before starting treatment.
Does TRT Cure Low Testosterone?
TRT can replace testosterone while treatment is being used, but it does not necessarily correct the underlying cause of testosterone deficiency.
In some cases, external testosterone can reduce the body's own testosterone and sperm production.
If treatment is stopped, the body's natural testosterone production may take time to recover.
For this reason, TRT should only be started after proper medical assessment and should be monitored regularly.
When Should You Speak With a Doctor?
Consider discussing your symptoms with a healthcare professional if you experience persistent:
Low sex drive
Erectile difficulties
Loss of morning erections
Unexplained fatigue
Loss of muscle strength
Increased body fat
Low mood
Concentration or memory problems
These symptoms can have many different causes, so testing and professional assessment are important before starting hormone treatment.
Important Information
DokterForYou does not sell medication.
The treatments mentioned in this article are examples of therapies that doctors may consider depending on the patient's symptoms, hormone levels, medical history, fertility goals, and overall health.
Final Thoughts
Low testosterone can affect sexual health, energy, muscle strength, mood, fertility, and overall quality of life.
Although testosterone levels naturally decline with age, persistent symptoms should not simply be dismissed as a normal part of getting older.
With appropriate testing and medical evaluation, the underlying cause can be investigated and suitable treatment options considered.
Testosterone replacement therapy may be appropriate for some men with confirmed testosterone deficiency, while others may benefit from addressing lifestyle factors or underlying medical conditions first.
At DokterForYou, our doctors can help assess your symptoms, review your medical history, and determine whether further testing or treatment may be appropriate.
👉 Take the first step toward understanding your testosterone levels and your overall health today.