How to Recognize Low Testosterone? Symptoms, Testing, and Treatment

Testosterone is a hormone that is, in a sense, the cornerstone of men’s health. It has decisive effects on muscle mass, bone density, sexual desire, energy, mood, and cognitive function. Low testosterone (hypogonadism), affecting millions of men in Turkey and worldwide, is often not noticed or is accepted as “a natural consequence of aging” and left unaddressed. Yet when diagnosed and appropriate treatment is initiated, quality of life can dramatically improve.

What Is Testosterone and Why Is It Important?

Testosterone is a steroid hormone produced primarily in the testes (in small amounts in the adrenal gland). In the male body, it performs the following functions:

Sexual desire and erection quality
Sperm production
Muscle mass and strength
Bone density
Red blood cell production
Fat distribution
Energy and motivation
Mood and cognitive functions

Normal Testosterone Levels

Group	Normal Range
Adult male (total)	300 – 1,000 ng/dL
Low threshold	< 300 ng/dL
Free testosterone	50–210 pg/mL

Important: Reference ranges may vary slightly between laboratories. Symptoms can appear even above 300 ng/dL; symptom evaluation is more important than numerical thresholds.

At What Age Does Testosterone Start to Decline?

Testosterone peaks at ages 25–30
After age 30, it decreases approximately 1–2% per year
Symptoms may become more apparent in the forties
At age 70, levels may be 30–50% lower than in the twenties

This decline is also referred to as “andropause” or “male menopause.”

Symptoms of Low Testosterone

Sexual Symptoms

Decreased libido (sexual desire)
Erectile dysfunction or decrease in erection quality
Decrease or disappearance of morning erections
Decrease in sperm count, infertility

Detailed information about erectile dysfunction →

Physical Symptoms

Decrease in muscle mass and strength
Increase in abdominal fat accumulation
Bone loss (risk of osteoporosis)
Decrease in body and facial hair
Breast enlargement (gynecomastia)
Hot flashes, sweating (especially in primary hypogonadism)

Psychological and Cognitive Symptoms

Chronic fatigue, loss of energy
Depression, irritability, mood swings
Difficulty concentrating, memory problems
Decrease in motivation

Sleep Problems

Difficulty falling asleep
Association with sleep apnea (one can worsen the other)

Causes of Low Testosterone

Primary Hypogonadism (Testicular Origin)

Klinefelter syndrome (47, XXY chromosome)
Testicular injury, torsion
Side effects of chemotherapy
Autoimmune damage

Secondary Hypogonadism (Pituitary/Hypothalamic Origin)

Prolactinoma (pituitary tumor)
Kallmann syndrome
Hemochromatosis
Idiopathic (unknown cause)

Functional (Treatable)

Obesity (adipose tissue converts testosterone to estrogen via the aromatase enzyme)
Type 2 diabetes
Chronic stress (cortisol suppression)
Sleep apnea
Anabolic steroid use
Opioid drug use

How Is It Tested?

The Right Time: Between 8–10 a.m.

Testosterone fluctuates throughout the day; it peaks in the morning. The test should be performed on an empty stomach, between 8–10 a.m.

Blood Tests

The following are requested in the initial evaluation:

Total testosterone (basic measurement)
Free testosterone (the biologically active portion)
SHBG (sex hormone-binding globulin)
LH and FSH (for primary-secondary differentiation)
Prolactin
Complete blood count, blood glucose, lipid panel

A single measurement is not sufficient; a low result should be repeated 2–4 weeks apart.

Treatment Methods

Testosterone Replacement Therapy (TRT)

Who is it right for?

Total testosterone below 300 ng/dL in two separate morning tests
Accompanying symptoms
No contraindications

TRT Forms:

Form	Application	Frequency
Transdermal gel	Shoulder/armpit	Every day
Intramuscular injection (short-acting)	Urology clinic or home	Every 2–3 weeks
Long-acting injection (Nebido)	Clinic	Every 10–14 weeks
Patch	Skin	Every day
Subcutaneous pellet	Minor surgery	Every 3–6 months

Benefits of TRT:

Libido and sexual function improve
Energy and mood improve
Muscle mass increases, fat decreases
Bone density is preserved

Risks and side effects of TRT:

Increase in red blood cells (erythrocytosis)
Testicular shrinkage, decrease in sperm count (a problem for those who want children)
Prostate stimulation (PSA monitoring is required)
Can worsen sleep apnea
Contraindicated in the presence of prostate or breast cancer

Clomiphene Citrate

A SERM used for testicular stimulation. Does not negatively affect fertility; an alternative for men who want children.

Increasing Testosterone Through Lifestyle

Resistance training (weightlifting)
Losing weight (especially abdominal fat)
Quality sleep (7–9 hours)
Stress management
Correcting deficiencies of zinc, vitamin D, and magnesium

Monitoring and Follow-Up

Men who start TRT should be regularly monitored with the following tests:

Testosterone level (every 3–6 months)
Hematocrit/hemoglobin (polycythemia risk)
PSA (prostate antigen)
Liver function tests
Lipid panel

Important Note: This content has been prepared for general informational purposes only. If low testosterone is suspected, please consult a urology, andrology, or endocrinology specialist.

Frequently Asked Questions (FAQ)

How is low testosterone identified with a blood test? Total and free testosterone are measured with a blood test taken on an empty stomach between 8–10 a.m. Below 300 ng/dL and the presence of significant symptoms are the basic criteria for diagnosis. A single measurement is not sufficient; it should be repeated 2–4 weeks apart.

What happens if low testosterone is not treated? In the long term, risks of muscle loss, bone loss, increased cardiovascular risk, metabolic syndrome, depression, and sexual dysfunction increase. Quality of life can significantly decline.

How long after starting TRT are effects seen? Libido and energy begin to improve in 2–6 weeks. Muscle mass becomes apparent in 3–6 months, bone density in 6–12 months. Full effect may take 12–18 months.

Does TRT cause dependence? Not in the sense of physical dependence; however, externally administered testosterone suppresses natural production. When TRT is stopped, it may take time for the hypothalamic-pituitary-testicular axis to recover. For this reason, stopping should be gradual and under specialist supervision.

Is anabolic steroid the same as TRT? No. TRT replenishes deficient testosterone to physiological levels; doses are within medical limits and under specialist supervision. Anabolic steroid use, on the other hand, is done at doses far exceeding physiological limits and carries serious health risks.

If sperm count is low, should testosterone treatment be started? TRT negatively affects sperm production by suppressing testosterone biosynthesis. In men who want children, clomiphene citrate or gonadotropin treatments are preferred over TRT.