Low Testosterone
Low testosterone -- clinically meaningful androgen deficiency with associated symptoms -- affects an estimated 2 -- 6% of men but is underdiagnosed. Many men attribute fatigue, low libido, and mood changes to normal aging rather than seeking evaluation. Identifying and treating true testosterone deficiency improves energy, sexual function, body composition, and mood.
Symptoms
Decreased sex drive, reduced morning erections, erectile dysfunction, fatigue, depressed mood, reduced motivation, decreased muscle strength, increased body fat, difficulty concentrating, and poor sleep quality.
Causes and risk
Testosterone declines naturally by 1 -- 2% per year after age 30. Accelerators include obesity (aromatase converts testosterone to estrogen in fat tissue), type 2 diabetes, sleep apnea, opioid use, anabolic steroid history, alcohol use disorder, and chronic illness. Secondary causes from the pituitary (including prolactinoma) must be excluded.
How it is evaluated
Total testosterone drawn between 7 -- 10 AM on two separate occasions is required for diagnosis. Free testosterone is useful when SHBG may be elevated (obesity, aging, hyperthyroidism). LH, FSH, and prolactin complete the endocrine picture. CBC, metabolic panel, and lipids assess metabolic health.
Treatment
Addressing reversible causes first: weight loss, sleep apnea treatment, opioid reduction, and alcohol moderation can meaningfully raise testosterone. When these are insufficient, TRT is discussed with attention to fertility plans. Clomiphene is preferred for men who wish to maintain fertility. All TRT methods are reviewed for patient preference.