Total Testosterone
Testosterone is the primary male sex hormone (and a smaller-quantity hormone in women). Low values in men cause fatigue, low libido and infertility; high values in women often signal PCOS.
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What it measures
Total testosterone is the sum of free testosterone, SHBG-bound and albumin-bound fractions. In men it is the principal androgen — driving libido, muscle mass, bone density, sperm production and mood. The standard draw is morning (08:00–10:00), fasting, on at least two occasions before diagnosing hypogonadism, because levels swing diurnally and acutely with illness. In women testosterone is produced in smaller quantities by ovaries and adrenals; elevation is the usual concern (PCOS, adrenal pathology).
Typical reference ranges
- Men: about 300-1000 ng/dL, gradually declining with age; best measured in a morning sample.
- Women: about 15-70 ng/dL.
- Levels swing through the day and drop with acute illness, so a low result is usually confirmed on a repeat morning test.
Your lab's printed range is what counts.
What a high value can mean
- In women: PCOS — most common; usually with elevated free androgen index, irregular periods, acne, hirsutism.
- Congenital adrenal hyperplasia, androgen-secreting tumour — rarer.
- Anabolic steroid use, testosterone replacement overdose — exogenous source.
- In men: rarely a concern in routine practice; very high points to exogenous use or testicular tumour.
What a low value can mean
- Male hypogonadism — primary (testicular) — Klinefelter, post-orchitis, chemotherapy.
- Male hypogonadism — secondary (pituitary) — pituitary tumour, opioid use, severe obesity, sleep apnoea, chronic illness.
- Age-related decline — modest, gradual; not all symptoms in older men respond to replacement.
- Stress, acute illness, recent intense exercise — transient drops.
Symptoms to look out for
- Low testosterone in men: low libido, fatigue, low mood, reduced muscle and strength, erectile difficulty, and sometimes poor concentration.
- In women, high testosterone can bring acne, excess hair growth and irregular periods (as in PCOS).
- Symptoms are non-specific and overlap with sleep, stress and thyroid problems - confirm before acting.
Many out-of-range results cause no symptoms at all - this is context, not a diagnosis.
When to discuss with a doctor
In a man with persistent symptoms (low libido, fatigue, erectile dysfunction) and morning total testosterone <300 ng/dL on two occasions, an endocrinology / urology consultation is appropriate to decide on replacement vs investigating the cause. In a woman with elevated testosterone plus irregular cycles or hirsutism, a PCOS work-up is the usual next step. Mediora.AI surfaces the threshold; replacement therapy belongs with a physician.