TESTOSTERONE - TOTAL

The Testosterone – Total test measures the overall amount of testosterone circulating in a blood sample. This includes testosterone bound to proteins such as Sex Hormone-Binding Globulin (SHBG) and albumin, together with the small amount that circulates in an unbound or free form.

Testosterone is an androgen hormone produced mainly by the testicles in males. Smaller quantities are produced by the ovaries in females and by the adrenal glands in both sexes. It contributes to sexual development, reproductive function, libido, sperm production, muscle mass, bone strength and red blood-cell production.

Total testosterone is commonly used as the initial laboratory test when symptoms suggest an abnormal testosterone level. The result must be interpreted according to age, sex, symptoms, collection time, medicine use and the laboratory's analytical method.

Benefits of the Test

• Measures the total concentration of circulating testosterone.
• Supports assessment of suspected testosterone deficiency in males.
• Contributes to the evaluation of male infertility and testicular function.
• Helps investigate androgen excess in females.
• Supports evaluation of early or delayed puberty.
• May help monitor testosterone or anti-androgen treatment.
• Provides baseline information before selected hormonal treatments.
• Can guide the need for additional tests such as LH, FSH, SHBG or free testosterone.

Why Doctors Recommend This Test

A doctor may recommend total testosterone testing for an adult male with symptoms that may be associated with testosterone deficiency. These can include reduced sexual desire, erectile difficulties, reduced spontaneous erections, infertility, loss of muscle mass, reduced facial or body hair, breast enlargement, low bone density or unexplained anaemia.

Symptoms alone cannot confirm testosterone deficiency because they may be caused by stress, poor sleep, obesity, chronic illness, medicines, depression, thyroid disease, relationship factors or other conditions. Diagnosis generally requires compatible symptoms together with consistently low testosterone results.

Because testosterone concentrations change during the day and can vary between days, an initial low result in an adult man is commonly confirmed using a second morning sample. Additional testing may include LH and FSH to help determine whether the cause is primarily testicular or related to the pituitary gland or hypothalamus.

In females, total testosterone may be requested when symptoms suggest androgen excess. These symptoms can include excess facial or body hair, persistent acne, scalp hair thinning, irregular or absent periods, voice changes or difficulty conceiving. Possible causes include polycystic ovary syndrome, medicine use and certain ovarian or adrenal disorders.

In children and adolescents, testing may help investigate puberty beginning earlier or later than expected. Results require age-, sex- and developmental-stage-specific interpretation by an appropriate specialist.

The test may also be used to monitor patients receiving testosterone replacement, gender-affirming hormone therapy, anti-androgen treatment or other medicines that affect androgen levels. Treatment monitoring should follow the schedule recommended by the treating doctor.

Preparation Before Test

For adult males, sample collection is commonly recommended during the morning, generally between approximately 7:00 AM and 10:00 AM, when testosterone concentrations are usually highest. The doctor may request a fasting morning sample to improve consistency.

Some patients may need to avoid food for several hours before collection. Follow the exact preparation instructions supplied by the doctor or laboratory. Plain water is generally permitted during fasting unless different instructions are provided.

Inform the doctor about testosterone therapy, anabolic steroids, opioid medicines, corticosteroids, anticonvulsants, hormonal contraceptives, fertility medicines, biotin and all other medicines or supplements. Do not stop prescribed treatment without medical advice.

Tell the healthcare professional about recent severe illness, poor sleep, strenuous exercise, major weight changes, testicular injury, surgery, chemotherapy or radiation treatment. Acute illness and other temporary factors may reduce testosterone and make the result unrepresentative of usual hormone status.

If monitoring testosterone treatment, the required collection time may depend on the medicine, dose and route of administration. Follow the treating doctor's instructions about when to collect the sample relative to the most recent dose.

Normal Reporting Time

The Total Testosterone test report is commonly available on the same day or within 24 hours after the laboratory receives a suitable blood sample. Reporting time may vary according to collection time, laboratory workflow, analytical method, quality-control checks and result verification.

Who Should Take This Test?

This test may be appropriate for males experiencing reduced libido, erectile difficulties, infertility, decreased muscle mass, reduced body hair, delayed puberty or other symptoms suggesting testosterone deficiency.

Females may require testing for persistent acne, excess facial or body hair, scalp hair thinning, irregular periods, infertility or other signs of androgen excess. Children may be tested when puberty begins unusually early or is delayed.

The test may also be requested for patients receiving hormone treatment or medicines that affect testosterone. It should be performed according to medical advice and not used as a stand-alone wellness or bodybuilding test.

Detailed Information

Most testosterone circulating in the blood is bound to SHBG or albumin. Only a small percentage is unbound. Total testosterone measures all these forms together, making it the most commonly used initial testosterone assessment.

Changes in SHBG may alter total testosterone without causing an equivalent change in biologically available hormone. SHBG may be affected by age, obesity, insulin resistance, thyroid disorders, liver disease and estrogen-containing medicines. When the total result does not match the symptoms, the doctor may request SHBG and free or bioavailable testosterone.

Low testosterone in males may be related to testicular injury or disease, pituitary or hypothalamic disorders, genetic conditions, obesity, severe chronic illness or certain medicines. Further investigation is required to determine the cause.

High testosterone in males may occur with anabolic-steroid or testosterone use and, less commonly, certain testicular or adrenal conditions. In females, elevated testosterone may occur with PCOS and selected ovarian or adrenal disorders.

A testosterone result alone cannot diagnose hypogonadism, infertility, PCOS or a tumour. In adult men, diagnosis of hypogonadism generally requires relevant symptoms and at least two unequivocally low morning testosterone measurements.

External testosterone can suppress LH and FSH and reduce sperm production. Men who are trying to conceive should not begin testosterone therapy without discussing fertility goals with an endocrinologist, urologist or fertility specialist.

Reference intervals vary considerably by sex, age, collection time and analytical method. Results should be interpreted using the range printed on the laboratory report and reviewed by a qualified healthcare professional.