What Is a Testosterone Test?

A testosterone test measures the amount of testosterone in the blood. Testosterone is involved in:

• Sexual desire
• Erectile and reproductive function
• Sperm production
• Muscle mass and strength
• Bone density
• Body hair growth
• Red blood cell production
• Mood and energy

Both men and women produce testosterone, although typical levels and reasons for testing differ. MedlinePlus: Testosterone Levels Test

Who Should Consider Testosterone Testing?

A doctor may recommend testing for men experiencing:

• Reduced sexual desire
• Fewer morning erections
• Erectile difficulties
• Persistent fatigue
• Reduced muscle mass or strength
• Increased body fat
• Mood or concentration changes
• Reduced facial or body hair
• Breast tissue enlargement
• Hot flashes
• Low sperm count or infertility
• Delayed or incomplete puberty
• Testicular injury or disease
• Possible pituitary dysfunction

These symptoms can also result from thyroid disease, diabetes, sleep disorders, depression, medication, stress, or other medical conditions.

Symptoms of Low Testosterone

Possible symptoms include:

• Low libido
• Reduced spontaneous erections
• Erectile dysfunction
• Low energy
• Reduced motivation
• Loss of muscle mass
• Increased abdominal fat
• Mood changes
• Difficulty concentrating
• Reduced bone density
• Anemia
• Infertility

Symptoms alone cannot confirm testosterone deficiency. Diagnosis requires appropriate blood testing and medical evaluation.

Symptoms of High Testosterone

High testosterone may be associated with:

• Non-prescribed testosterone use
• Anabolic steroid use
• Excessive TRT dosing
• Testicular or adrenal conditions
• Certain hormonal disorders

Possible signs include:

• Acne or oily skin
• Increased body hair
• Mood or behavioral changes
• Elevated red blood cell count
• Reduced sperm production
• Testicular shrinkage
• Changes in sexual function

Some patients with elevated levels have no obvious symptoms.

Types of Testosterone Tests

Total Testosterone

Total testosterone includes hormone that is:

• Bound to SHBG
• Weakly bound to albumin
• Circulating freely

It is usually the initial test used when testosterone deficiency is suspected.

Free Testosterone

Free testosterone measures or estimates the small portion that is not bound to proteins.

It may be particularly useful when total testosterone does not match the patient’s symptoms or when SHBG levels may be abnormal.

SHBG Test

Sex hormone-binding globulin, or SHBG, is a protein that carries testosterone and other sex hormones in the blood.

Changes in SHBG can affect the relationship between total and biologically available testosterone. MedlinePlus: SHBG Blood Test

Bioavailable Testosterone

Bioavailable testosterone includes free testosterone and testosterone weakly bound to albumin. It may be calculated or measured in selected cases.

When Should Testosterone Be Tested?

Testosterone levels normally fluctuate throughout the day and are generally higher earlier in the morning.

For men being evaluated for possible hypogonadism, blood collection is commonly scheduled in the early morning. Shift work, sleep patterns, acute illness, fasting instructions, and medication can affect the recommended timing.

The Endocrine Society recommends confirming suspected testosterone deficiency with a repeat morning fasting total testosterone measurement. Endocrine Society Guideline

Why Is Repeat Testing Necessary?

Testosterone levels may temporarily decrease because of:

• Poor sleep
• Acute illness
• Severe stress
• Calorie restriction
• Heavy exercise
• Medication
• Alcohol use
• Obesity
• Laboratory variation

A single low result does not necessarily confirm chronic testosterone deficiency.

Diagnosis generally requires:

• Symptoms consistent with deficiency
• Consistently low testosterone levels
• Properly timed testing
• Interpretation using the laboratory’s reference range
• Evaluation for the underlying cause

Additional Hormone Tests

When testosterone is low or symptoms are significant, the doctor may recommend additional testing.

LH

Luteinizing hormone signals the testicles to produce testosterone. LH results can help determine whether low testosterone is primarily related to the testicles or to the pituitary and hypothalamus.

FSH

Follicle-stimulating hormone supports sperm production. It may be tested when fertility or testicular function is a concern.

Prolactin

Elevated prolactin can contribute to low testosterone, reduced libido, infertility, or erectile dysfunction. Markedly abnormal results may require pituitary evaluation.

Estradiol

Estradiol may be measured when patients have breast enlargement, obesity, liver disease, infertility, or concerns related to testosterone therapy.

Thyroid Testing

Thyroid conditions can cause fatigue, mood changes, sexual symptoms, weight changes, and altered SHBG levels.

Other Tests That May Be Recommended

A broader evaluation may include:

• Complete blood count
• Blood glucose or HbA1c
• Cholesterol testing
• Liver and kidney function
• PSA testing when appropriate
• Iron testing
• Semen analysis
• Sleep apnea assessment
• Pituitary MRI in selected cases

Not every patient requires every test.

How to Prepare for a Testosterone Test

The clinic may advise patients to:

• Schedule testing in the morning
• Fast when instructed
• Avoid unusually strenuous exercise beforehand
• Maintain a normal sleep schedule when possible
• Bring a list of medications and supplements
• Report testosterone, steroid, or hormone use
• Mention recent illness
• Provide previous hormone results

Do not stop prescribed medication without medical guidance.

Medications That May Affect Testosterone

Testosterone levels may be influenced by:

• Opioids
• Corticosteroids
• Hormonal medication
• Anabolic steroids
• Testosterone therapy
• Certain prostate medications
• Some psychiatric medication
• Chemotherapy

Patients should disclose prescription, non-prescription, and performance-enhancing substances.

Understanding Testosterone Test Results

Reference ranges vary according to:

• Laboratory
• Testing method
• Age
• Sex
• Time of collection
• SHBG level
• Health status

A result marked “low” or “normal” should not be interpreted without considering symptoms and testing conditions.

The diagnosis of hypogonadism should be based on compatible symptoms together with consistently low testosterone—not a single result alone.

Low Testosterone With High LH or FSH

Low testosterone with elevated LH or FSH may suggest that the testicles are not responding adequately to hormonal signals.

Possible causes include:

• Testicular injury
• Previous infection
• Chemotherapy or radiation
• Genetic conditions
• Testicular surgery
• Age-related testicular dysfunction

Further evaluation may be recommended.

Low Testosterone With Low or Normal LH

Low testosterone with an inappropriately low or normal LH level may suggest a pituitary or hypothalamic cause.

Possible contributing factors include:

• Obesity
• Chronic illness
• Opioid medication
• Elevated prolactin
• Pituitary conditions
• Severe calorie restriction
• Previous anabolic steroid use

Additional hormone testing and imaging may be required.

Testosterone Testing and Male Fertility

Testosterone testing may be included in a male infertility evaluation, but it does not directly measure sperm quality.

Fertility evaluation may also include:

• Semen analysis
• FSH and LH
• Prolactin
• Genetic testing
• Scrotal ultrasound
• Physical examination

External testosterone therapy can reduce or stop sperm production. Men planning children should discuss fertility before beginning TRT.

Testosterone Testing Before TRT

Before prescribing testosterone replacement therapy, the doctor should confirm that the patient has both relevant symptoms and consistently low hormone levels.

The evaluation may also review:

• Fertility goals
• Prostate health
• Blood count
• Sleep apnea
• Cardiovascular history
• Breast symptoms
• Previous hormone use
• Possible underlying causes

TRT is not an appropriate treatment for every patient with fatigue or erectile dysfunction.

Monitoring During Testosterone Therapy

Patients already receiving TRT may require periodic testing of:

• Testosterone levels
• Complete blood count
• PSA when appropriate
• Liver and metabolic health
• Blood pressure
• Treatment response
• Side effects

The timing of blood collection may depend on whether the patient uses injections, gels, patches, or another formulation.

Patients should tell the clinic when their most recent dose was taken or applied.

Testosterone Tests for Women

Women may undergo testosterone testing for:

• Excess facial or body hair
• Acne
• Scalp hair loss
• Irregular menstrual cycles
• Infertility
• Polycystic ovary syndrome
• Possible ovarian or adrenal conditions
• Signs of virilization

Testing may include total testosterone, free testosterone, SHBG, DHEA-S, and other reproductive hormones.

Testosterone Testing for International Patients

Busan offers testosterone testing through urology, endocrinology, fertility, internal medicine, and men’s health clinics. English-language support varies by facility.

International patients should bring:

• Previous testosterone results
• A list of medications and supplements
• Details of TRT or steroid use
• Fertility records
• Relevant pituitary or testicular records
• Information about sleep apnea
• PSA and blood-count results when available
• The timing of the most recent hormone dose

Patients staying in Korea briefly should ask whether repeat morning testing and follow-up can be completed before departure.

How Long Do Testosterone Results Take?

Blood collection may be completed during one visit. Processing time depends on:

• Total or free testosterone testing
• Testing method
• Number of additional hormones
• Whether specialized testing is required
• Clinic laboratory arrangements

A low result may require another morning blood test before diagnosis or treatment.

Testosterone Test Cost in Busan

The total cost may depend on:

• Medical consultation
• Total testosterone
• Free testosterone
• SHBG
• LH and FSH
• Prolactin
• Estradiol
• Thyroid testing
• Blood count and metabolic testing
• PSA testing
• Semen analysis
• Pituitary or testicular imaging
• Follow-up consultation

Patients should request an individualized estimate based on the required hormone panel.

When Should You Seek Prompt Medical Care?

Arrange prompt evaluation for:

• Sudden testicular pain or swelling
• Severe headache with vision changes
• New breast discharge
• Rapid loss of sexual development
• Symptoms after stopping anabolic steroids
• Severe weakness or fainting
• Significant mood or behavioral changes
• Fertility concerns with testicular abnormalities

These symptoms may indicate a testicular, pituitary, or other medical condition requiring timely evaluation.

Frequently Asked Questions

Is one testosterone test enough?

Usually not when diagnosing testosterone deficiency. A low result should generally be confirmed with another properly timed morning test.

Should I fast before a testosterone test?

Morning fasting testing is commonly recommended when evaluating possible male hypogonadism. Follow the clinic’s exact instructions.

What is the difference between total and free testosterone?

Total testosterone includes bound and unbound hormone. Free testosterone represents the small unbound portion and may help when SHBG is abnormal.

Can testosterone testing diagnose infertility?

No. It evaluates hormonal status but does not measure sperm count or quality. A semen analysis is usually required.

Can I test testosterone while using TRT?

Yes, but the result must be interpreted according to the formulation, dose, and timing of the last treatment.

Can international patients get testosterone testing in Busan?

Yes. International patients can receive morning testosterone testing, related hormone panels, fertility evaluation, and medical interpretation in Busan.