Testosterone, Total and Free
Testosterone is the major sex hormone in men. Testosterone levels begin to decline around 40 years of age. By 80 years of age, more than 50% of men will have testosterone levels in the low range. Studies show that 38% of the men going to the doctors have low testosterone.
Women make smaller amounts of testosterone. In both men and women, testosterone is an important anabolic hormone. This means it’s important for creating and maintaining the health of cells and organs throughout the body, such as for building muscle, nerves, skin and bones.
- Total testosterone
- Free Testosterone
Methodology: Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/MS), Tracer Equilibrium Dialysis, Calculation (CALC)
Fasting: Not required.
Water: Drink plenty of water to stay well hydrated.
Medications: Take all medications as prescribed.
4-5 business days
Result turnaround times are estimates and not guaranteed. Due to factors outside of our control, such as weather, holidays, confirmation/repeat testing or equipment maintenance, our lab may require additional time to complete tests.
Measuring testosterone can help diagnose the cause of many conditions, including erectile dysfunction and infertility in men and infertility, virilization, and polycystic ovarian syndrome (PCOS) in women.
Low testosterone can cause or contribute to:
- Cardiovascular disease
- Chronic obstructive pulmonary disease (COPD)
- Chronic kidney disease (CKD)
- Decreased memory
- Erectile dysfunction
- Low sperm counts
- Muscle loss (sarcopenia)
Testosterone can be found in its free form and its bound form. 1-2% of testosterone floats around the body on its own as free biologically active testosterone. The remainder of the testosterone is bound to proteins called albumin and sex hormone binding globulin. Total testosterone measures both free and bound testosterone.
Low Testosterone and Your Health (WebMD)
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Petering RC, Brooks NA. Testosterone Therapy: Review of Clinical Applications. Am Fam Physician. 2017;96(7):441-449.
Seftel AD. Re: PS3-36: testosterone replacement therapy patterns for aging males in a managed care setting. J Urol. 2014;191(3):751.
Wittert G. The relationship between sleep disorders and testosterone. Curr Opin Endocrinol Diabetes Obes. 2014;21(3):239-243.