Description: Testosterone, Total, MS is a blood test used to detect abnormal levels of testosterone in both male and female patients, and diagnose causes of erectile dysfunction, infertility, virilization, polycystic ovary syndrome, and delayed or early puberty in children.
Also Known As: Total Testosterone Test, Testosterone Total Test, Female Testosterone Test, Pediatric Testosterone Test, Ultrasensitive Testosterone Test, Uncapped Testosterone Test
Collection Method: Blood Draw
Specimen Type: Serum
Test Preparation: No preparation required
When is a Testosterone Total test ordered?
When infertility is suspected, or when a man has decreased sex drive or erectile difficulties, a testosterone test may be ordered. Other signs include a lack of beard and body hair, a loss of muscle mass, and the formation of breast tissue. Low total and bioavailable testosterone levels have also been linked to, or caused by, increased visceral fat, insulin resistance, and an increased risk of coronary artery disease.
The test is frequently ordered in conjunction with the FSH and LH tests in males who are experiencing delayed or slow puberty. Although the age at which puberty begins varies from person to person, it usually begins around the age of ten. The following are some of the signs and symptoms of delayed puberty:
- Muscle mass development is delayed.
- Voice not getting lower or a lack of body hair growth
- Growth of the testicles and penis is slowed or delayed.
When a young boy appears to be going through an early puberty with clear secondary sex traits, the test can be ordered. Various malignancies and congenital adrenal hyperplasia can cause early puberty in boys due to elevated testosterone.
When a woman has irregular or no menstrual cycles, is having trouble getting pregnant, or displays masculine traits such as abundant facial and body hair, male pattern baldness, and/or a low voice, testosterone testing may be done. Testosterone levels can rise as a result of malignancies in the ovary or adrenal gland, as well as other illnesses including polycystic ovarian syndrome.
What does a Testosterone Total blood test check for?
In men, testosterone is the primary sex hormone. It's in charge of a man's physical appearance. Although it is thought to be a "masculine" sex hormone, it is found in both men and women's blood. This test determines the amount of testosterone in a person's blood.
Testosterone is primarily produced in the male testicles by unique endocrine tissue called Leydig cells. It's also made by the adrenal glands in both males and females, as well as the ovaries in females in modest amounts.
In males, testosterone promotes the formation of secondary sex characteristics such as penis size, body hair growth, muscle development, and a deeper voice. It is abundant in males during adolescence and adulthood in order to regulate sex drive and preserve muscle mass. Estradiol is the major sex hormone in females, and testosterone is converted to it in women.
The pituitary gland produces luteinizing hormone, which stimulates and regulates testosterone synthesis. Testosterone functions in a negative feedback loop: when testosterone levels rise, LH production falls, slowing testosterone production; lower testosterone levels cause higher LH production, which promotes testosterone production.
Testosterone levels fluctuate throughout the day, increasing in the early morning hours and dropping in the evening. Levels rise after activity and fall as people get older.
About two-thirds of testosterone is attached to sex-hormone binding globulin in the bloodstream, with the remaining one-third bound to albumin. Only a small percentage of testosterone is released into the bloodstream as free testosterone. The bioavailable fraction is the free plus albumin-bound testosterone, which can act on target tissues.
In many circumstances, measuring total testosterone is sufficient information for a healthcare provider. A test for free or bioavailable testosterone may be performed in some circumstances, such as when the level of SHBG is abnormal, as it may more accurately indicate the presence of a medical issue.
Lab tests often ordered with a Testosterone Total test:
- Anti-mullerian Hormone
- Sex Hormone Binding Globulin
Conditions where a Testosterone Total test is recommended:
- Polycystic Ovary Syndrome
- Hypothalamic disease
- Pituitary disease
- Liver disease
- Eating disorders
- Cushing Syndrome
- Testicular cancer
- Adrenal insufficiency
- Congenital Adrenal Hyperplasia
Commonly Asked Questions:
How does my health care provider use a Testosterone Total test?
In men, women, girls, and boys, testosterone testing is used to identify a variety of problems. Testosterone is the major sex hormone in males, and it is responsible for masculine physical traits. It is produced mostly by the testicles. Although it is thought to be a "male" sex hormone, it is found in both males and females.
The testosterone test can be used to determine whether or not you're experiencing:
- Delayed or early puberty in boys
- In both men and women, sex drive has decreased.
- Men's erectile dysfunction
- Male and female infertility
- Tumors of the testicles in men
- Disorders of the hypothalamus or pituitary gland
- Virilization and hirsutism in girls and women
A testosterone total test is usually used to diagnose a condition. The free and total testosterone test distinguishes between testosterone that is bound to proteins in the blood and testosterone that is not attached to proteins.
About two-thirds of testosterone is tied to SHBG in the blood, with the remaining one-third attached to albumin. Free testosterone circulates in a tiny percentage. Bioavailable testosterone is made up of free testosterone and testosterone bound to albumin, and it can operate on target tissues.
A test for free or bioavailable testosterone may be performed in some circumstances, such as when the level of SHBG is abnormal, as it may more accurately indicate the presence of a medical issue.
Other tests and hormone levels may be performed in conjunction with testosterone testing, depending on the reason for testing. Here are a few examples:
What does my testosterone test result mean?
Testosterone levels often begin to fall after the age of 30. Testosterone levels may drop more in obese or chronically unwell men, as well as with the use of certain drugs.
Hypogonadism can be caused by a variety of factors, including:
- Pituitary or hypothalamic illness
- Reduced testosterone production in young males can be caused by genetic disorders
- Possible infertility or testicular failure
- Acquired damage to the testes, such as from drinking, physical injury, or viral infections like mumps, reduces testosterone production.
Healthcare practitioners may recommend testosterone replacement therapy to men who have consistently low testosterone levels and associated signs and symptoms. The Food and Drug Administration has not approved testosterone supplements to improve strength, sports performance, or avoid aging disorders. It's possible that using it for these purposes is dangerous.
Increased testosterone levels in men can mean one of several things:
- Tumors of the testicles
- Testosterone-producing tumors in the adrenal glands
- Use of anabolic steroids
- Early puberty in males due to an unknown cause
- Adrenal hyperplasia in toddlers and babies
Testosterone levels in women are typically low. Increased testosterone levels can mean one of the following things:
- Ovarian or adrenal gland tumor
- Adrenal hyperplasia that occurs at birth.
We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.