The free testosterone test measures the amount of hormone available for use, while the total testosterone test measures the total amount produced by the body. These results can help identify hormonal imbalances and conditions like liver disease. Learn in which medical situations these tests are recommended.
Testosterone, essential for both men and women, plays crucial roles, from regulating libido to promoting muscle development and bone density. Free and total testosterone tests are indispensable tools to uncover potential hormonal imbalances that can affect not only physical health but also quality of life.
In this article, you’ll discover the importance of these tests, when to perform them, and what their results can reveal about your health.
What are free and total testosterone tests for?
Free and total testosterone tests are performed to evaluate the levels of testosterone in the body, helping doctors understand hormonal health in both men and women. They are used for:
- Total testosterone: measures the total amount of testosterone in the body, including that bound to proteins such as sex hormone-binding globulin (SHBG). This test is useful for evaluating the body’s ability to transport and store testosterone, which can impact various metabolic processes and hormonal functions.
- Free testosterone: analyzes the fraction of testosterone not bound to proteins (about 2-3% of total testosterone). This biologically active portion performs essential functions such as regulating physical characteristics, stimulating libido, developing muscle mass and strength, and maintaining bone density.
These tests are indicated to diagnose hormonal imbalances such as low testosterone (hypogonadism), fertility problems, libido changes, and to monitor general health in different clinical conditions.
When are free and total testosterone tests recommended?
Free and total testosterone tests for men are recommended in cases of low libido, erectile dysfunction, fertility issues, and hormonal imbalances due to diseases or testicular removal, often following prostate cancer.
These tests are also useful for investigating early or delayed puberty.
For women, this hormonal analysis helps uncover the causes of excess testosterone.
When are results normal or abnormal?
Reference values for free and total testosterone vary by a man’s age. See below:
Total testosterone
- 22 to 49 years: 241 to 827 ng/dL;
- 50 years and older: 86.49 to 788.22 ng/dL.
Free testosterone
- 17 to 40 years: 3 to 25 ng/dL;
- 41 to 60 years: 2.7 to 18 ng/dL;
- 60 years and older: 1.9 to 19 ng/dL.
Abnormal free and total testosterone results may indicate:
Low total and free testosterone
- Hypogonadism: irregular testosterone production due to testicular issues or problems in the hypothalamus or pituitary gland, leading to chronic fatigue, muscle loss, mood changes, and erection difficulties;
- Liver failure: SHBG is a protein that helps transport testosterone. Since much of its production occurs in the liver, diseases in this organ can affect male hormone levels;
- Klinefelter syndrome: a genetic condition where boys are born with an extra X chromosome, leading to breast tissue enlargement, lack of body hair, reduced muscle mass, and inadequate penis development.
High total and free testosterone
- Adrenal hyperplasia: excessive testosterone production due to adrenal gland dysfunction, often caused by a deficiency in the 21-hydroxylase enzyme. In boys, this can cause early puberty, while adults may experience excessive hair growth, low libido, and erection problems.
- Hyperthyroidism: increases thyroid hormone production, raising SHBG levels, which bind to sex hormones. More SHBG means higher total testosterone but lower free testosterone, affecting physical traits, sexual function, bone density, and muscle development.
What to do if testosterone is unbalanced?
If free and total testosterone tests confirm hormonal imbalance, treatment varies according to the specific condition. See below:
- High testosterone: medications to reduce testosterone production. If the patient uses anabolic steroids, discontinuation is required;
- Low testosterone: hormone replacement therapy, physical activity, and foods rich in vitamin D, zinc, and proteins.
Medical monitoring is essential
As important as the diagnosis is, medical follow-up during treatment for any hormonal deficiency is crucial. Monitoring allows for regular blood tests, evaluation of side effects, and dosage adjustments if needed. Do not ignore the signs your body may be sending.
Seek a trusted doctor to assess your hormonal health and recommend the best treatment, always prioritizing overall well-being.
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