What this marker measures
Total testosterone includes both bound and free fractions. Free testosterone (the biologically active form, not bound to proteins) can be measured separately and may better reflect symptoms, particularly when SHBG is abnormal.
High or low: what it can mean
High Testosterone
Testosterone above the reference range in females can be associated with conditions such as polycystic ovary syndrome (PCOS) or adrenal and ovarian conditions. In males, very high levels may be linked to anabolic steroid use or certain tumors.
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Low Testosterone
Low testosterone in males (hypogonadism) can cause fatigue, reduced libido, mood changes, reduced muscle mass, and bone loss. In females, low testosterone can also affect energy and libido, though the clinical significance of borderline values is debated.
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Lifestyle considerations
- •Sleep, stress management, and maintaining a healthy weight support testosterone levels
- •Testosterone naturally declines gradually with age in both sexes
Frequently asked questions
What is Testosterone?
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Testosterone is the primary male sex hormone, though it is present and important in females too. It supports muscle mass, bone density, libido, mood, red blood cell production, and fat distribution.
What does Testosterone measure?
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Total testosterone includes both bound and free fractions. Free testosterone (the biologically active form, not bound to proteins) can be measured separately and may better reflect symptoms, particularly when SHBG is abnormal.
What does high Testosterone mean?
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Testosterone above the reference range in females can be associated with conditions such as polycystic ovary syndrome (PCOS) or adrenal and ovarian conditions. In males, very high levels may be linked to anabolic steroid use or certain tumors.
What does low Testosterone mean?
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Low testosterone in males (hypogonadism) can cause fatigue, reduced libido, mood changes, reduced muscle mass, and bone loss. In females, low testosterone can also affect energy and libido, though the clinical significance of borderline values is debated.
What supports healthy Testosterone levels?
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Sleep, stress management, and maintaining a healthy weight support testosterone levels. Testosterone naturally declines gradually with age in both sexes
Related biomarkers
Editorial note
LabTestly explains lab markers using plain-English educational content. Reference ranges may vary by laboratory and should be interpreted with a clinician.
Educational content · Editorially reviewed for clarity · Last updated
Common sources used for lab-test education
Not medical advice
This page is for general understanding only and does not replace medical advice from your clinician. Reference ranges can vary by laboratory, age, sex, pregnancy status, medications, and clinical context.