1013. Total Testosterone (T total, serum)

Testosterone is a hormone from the androgen group that is present in both men and women, but in different amounts. The test helps assess testosterone levels in cases of disorders of puberty and the menstrual cycle, difficulties conceiving, excessive hair growth on the face and body in women, as well as decreased sexual desire or problems with erection in men. Testosterone levels change throughout the day and are usually highest in the morning.

A physician may recommend assessing total testosterone together with sex hormone-binding globulin (SHBG), a protein that transports sex hormones in the blood. This helps assess hormonal status more accurately, particularly if changes in SHBG levels may affect the total testosterone result.

Testosterone is the main hormone from the androgen group. Androgens are often referred to as male sex hormones; however, they are produced in both the male and female body. The main difference is their amount: testosterone levels are significantly higher in men.

In men, most testosterone is produced by the testes. In women, a small amount of the hormone is produced by the ovaries and adrenal glands. Its production is regulated by signals from the brain and the pituitary gland, a small gland that controls the function of other glands in the body.

During puberty, testosterone levels increase. The hormone is involved in the development of male sexual characteristics, including facial and body hair growth, lowering of the voice, development of the reproductive organs, and an increase in muscle mass. In adult men, testosterone affects sexual desire, sperm production, muscle strength, and bone strength. In women, it also plays a role in the function of the reproductive system, maintenance of muscle and bone tissue, and regulation of sexual desire.

In the blood, testosterone is predominantly bound to proteins, namely sex hormone-binding globulin (SHBG) and albumin. Only a small proportion is present in free form. The total testosterone test measures the total amount of bound and free hormone in the blood. This is the test included in this service. Free testosterone is measured or calculated separately, for example, when the total testosterone result does not correspond to the existing symptoms or when changes in SHBG levels may affect its assessment.

Testosterone levels depend on sex, age, and the condition of the body. In men, levels change throughout the day: they are usually highest in the morning and gradually decrease in the evening. A temporary decrease may occur during an acute or severe illness, with inadequate nutrition, excessive physical exercise, insufficient sleep, or under the influence of certain medications.

In women, the result is assessed taking into account age, symptoms, hormone therapy, pregnancy, and other laboratory parameters. Testosterone testing is part of laboratory diagnostics, but a single measurement cannot determine the cause of symptoms or establish a definitive diagnosis.

What Do Testosterone Test Results Mean?

For total testosterone, the laboratory indicates reference values on the test report – a range against which the obtained result is compared. These ranges depend on sex, age, and the testing method.

The result is assessed together with symptoms, health status, the time of blood collection, use of medications, and other test results. An elevated or decreased level may have various causes and, by itself, does not confirm a specific disease.

Low Testosterone in Men

A decreased level may be associated with:

• impaired testicular function due to congenital conditions, injury, infection, or other diseases;
• impaired function of the pituitary gland or hypothalamus – areas of the brain that regulate testosterone production;
• acute, severe, or prolonged illnesses;
• the use of certain medications, in particular some medications used to treat severe pain, as well as anabolic steroids (medications that have effects similar to testosterone and may be used to increase muscle mass);
• chemotherapy, radiation therapy, or treatment aimed at reducing testosterone levels in the presence of prostate cancer.

Low testosterone may be accompanied by decreased sexual desire, problems with achieving or maintaining an erection, increased fatigue, worsening mood, decreased muscle mass, loss of facial or body hair, enlargement of the breasts, or difficulties conceiving. These symptoms may also have other causes. Therefore, testosterone deficiency (a condition in which the body does not have enough of this hormone) is not determined solely on the basis of a blood test. Characteristic symptoms and the results of at least two tests performed in the morning on different days are taken into account.

If a low result is obtained, a physician may recommend a repeat testosterone test, as well as testing for luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin, sex hormone-binding globulin (SHBG), free testosterone, or other examinations.

High Testosterone in Men

An elevated level is most often associated with the use of testosterone preparations or anabolic steroids and, less commonly, with diseases of the testes or adrenal glands. In children and adolescents, a high level may accompany excessively early onset of puberty.

High Testosterone in Women

An elevated level may be observed in polyendocrine metabolic ovarian syndrome (previously referred to as polycystic ovary syndrome, PCOS) – a common hormonal and metabolic condition that may be accompanied by irregular menstruation, excessive facial and body hair growth, acne, and difficulties conceiving. Other possible causes include diseases of the ovaries or adrenal glands, as well as the use of preparations containing testosterone or other androgens.

An elevated level may be accompanied by:

• irregular or absent menstruation;
• excessive growth of dark, coarse hair on the face and body;
• acne;
• male-pattern hair loss on the scalp;
• difficulties conceiving.

Sudden onset or rapid worsening of such changes, lowering of the voice, or other signs of pronounced androgen excess require consultation with a physician. To determine the cause, testing for SHBG, the free androgen index, and other hormones, as well as imaging and other diagnostic may be required.

Testosterone: When Should It Be Tested?

Testing for testosterone is appropriate when symptoms of a possible increase or decrease in hormone levels, disorders of puberty, menstrual cycle disorders, or impaired ability to conceive are present.

The test is also used to monitor hormone levels during treatment with testosterone preparations or therapy aimed at reducing testosterone levels.

For the initial assessment of possible testosterone deficiency in men, a physician usually recommends having blood drawn in the morning, when hormone levels are highest. If the result is low, the test may be repeated in the morning on another day.

During treatment with testosterone preparations, the timing of blood collection may depend on the form of the preparation and the time of its most recent use. In this case, the physician’s recommendations should be followed.

Who Needs a Testosterone Test?

The test may be recommended for:

• children and adolescents if puberty has started too early or, conversely, is delayed;
• men with decreased sexual desire, problems with achieving or maintaining an erection, or other signs of possible testosterone deficiency;
• men with decreased muscle mass, loss of facial or body hair, breast enlargement, or prolonged increased fatigue;
• men and women when investigating the causes of difficulties conceiving;
• women with irregular or absent menstruation, excessive facial and body hair growth, acne, or hair loss on the scalp;
• women with suspected polyendocrine metabolic ovarian syndrome (PMOS);
• suspected diseases or tumors of the testes, ovaries, or adrenal glands that may affect testosterone production;
• during treatment with testosterone preparations – to monitor hormone levels;
• during treatment for prostate cancer with medications that lower testosterone levels – to assess the response to treatment.

• Venous blood

In order to exclude factors that may affect the test results, we recommend to follow the preparation rules: