Definition

A testosterone test measures the levels of testosterone in the body. Testosterone is produced primarily by the testes in men, the ovaries in women, and the adrenal glands in both sexes.

Testosterone is the primary sex hormone in men, responsible for various changes during puberty, such as the development of body and facial hair, increased muscle mass, and a deeper voice. In adult men, testosterone plays a crucial role in sexual arousal and sperm production.

While testosterone is predominantly associated with men, women also produce this hormone in smaller amounts. In women, testosterone supports bone and muscle development and contributes to the health of other organs.

In the bloodstream, most testosterone binds to proteins, but some remains unbound, referred to as free testosterone. Testing measures both total and free testosterone levels to help diagnose specific health conditions:

• Total Testosterone: Includes both protein-bound and free testosterone.
• Free Testosterone: Measures only the unbound testosterone in the blood.

Indications

The testosterone test is performed for several reasons, including:

• Diagnosing conditions associated with abnormal testosterone levels (either low or high).
• Determining the cause of premature or delayed puberty in children and adolescents.

Doctors may also recommend this test in the following situations:

• Difficulty conceiving.
• Erectile dysfunction (problems achieving or maintaining an erection).
• Loss of sexual desire.
• In women, signs of masculinity such as excessive body hair or a deepening voice.
• Presence of testicular tumors.

Contraindications

There are no specific contraindications for testosterone testing. The test is generally considered safe for individuals of all age groups.

Preparation Prior to Test

No special preparation is required for a testosterone test, which is typically conducted in the morning (7–10 am). Fasting is not necessary for this test.

It is advisable to consult your doctor beforehand, as certain factors may interfere with the accuracy of the test results and the test will end up not portray your true condition.

You should inform your doctor about any medications or supplements you are currently taking, as they might recommend discontinuing these before the test.

Test Procedure

The testosterone test involves collecting a blood serum sample of 0.25–0.5 mL. The blood sample is drawn from a vein and stored in a special tube for analysis. Laboratory staff use personal protective equipment (PPE) during the procedure to ensure safety.

Before taking the blood sample, the staff will attach an elastic band around your upper arm to make veins more visible. The skin at the needle insertion site is cleaned with antiseptic gauze. Blood is drawn from a vein, typically in the elbow crease area, and collected in a special tube. After the blood is collected, the elastic band is removed, and the puncture site is pressed and cleaned with antiseptic gauze.

This procedure usually takes only a few minutes. The collected sample is sent to the laboratory, and the results are typically available within a few hours.

Normal and Abnormal Values

Testosterone levels vary by gender and age, with normal ranges defined as follows:

Men 

Women

Based on the table, the lower and upper limits of the normal range vary according to age and gender. Testosterone levels are considered abnormal if they fall below or exceed these ranges. It is important to note that normal ranges may vary slightly between laboratories due to differences in testing equipment or methods.

Abnormal testosterone levels, whether low or high, should be interpreted in the context of an individual's age, gender, and overall health.

Results and Recommendations (Follow-up Tests)

Low

If testosterone test results indicate low levels, it is essential to consult a doctor. Low testosterone levels in men may suggest the following conditions:

• Chronic diseases such as liver or kidney disease.
• Pituitary gland abnormalities, small glands in the brain.
• Benign tumors.
• Testicular injury.
• Alcohol abuse.
• Genetic disorders, such as Klinefelter syndrome.

In women, low testosterone levels are generally normal. However, if values are significantly low, they may indicate:

• Adrenal gland abnormalities, small glands above the kidneys.
• Pituitary gland abnormalities.
• Ovarian disorders.

Normal

Normal testosterone levels generally indicate a healthy hormonal balance and no abnormalities in the testicles, ovaries, or pituitary gland, assuming no specific symptoms or clinical signs are present.

Maintaining a healthy lifestyle is advised to prevent conditions such as chronic diseases or tumors associated with abnormal testosterone levels.

High 

Elevated testosterone levels in men may suggest:

• Testicular tumors.
• Steroid drug use.
• Adrenal gland abnormalities, such as congenital adrenal hyperplasia (a congenital disorder affecting hormone production).

In women, high testosterone levels may be caused by:

• Polycystic ovary syndrome (PCOS).
• Ovarian cancer.
• Adrenal gland abnormalities, such as congenital adrenal hyperplasia.
• Pituitary gland abnormalities.

Consult the Right Doctor

Adult patients with abnormal testosterone levels should consult a general practitioner for further diagnosis and treatment. Specialists such as andrologists (for men) or gynecologists (for women) may be needed for more specific testosterone-related concerns. Pediatric patients with abnormal results should consult a pediatrician for appropriate evaluation and care.

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