Estimate your risk of hereditary hair loss (androgenetic alopecia) based on key family predictors including maternal grandfather, father, and paternal family hair patterns.
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⚠️ Educational only. Probability estimates based on genetic models, not medical advice.
Androgenetic alopecia affects approximately 50% of men by age 50 and around 25% of women by age 50. Despite its prevalence, the genetics are complex: over 280 variants across multiple chromosomes contribute to risk, making it one of the most polygenic traits in human genetics research.
Androgenetic alopecia is the most common cause of hair loss in both men and women. It is caused by genetic sensitivity of hair follicles to dihydrotestosterone (DHT), primarily controlled by variants in the AR gene on the X chromosome and over 280 additional autosomal variants.
The androgen receptor gene on the X chromosome is the most significant known contributor to male pattern baldness. Men inherit their X from their mothers, which is why the maternal grandfather's hair pattern is the strongest single predictor for male children. However, AR accounts for only about 40% of genetic risk.
Over 280 genetic variants across both X and autosomal chromosomes are now associated with androgenetic alopecia. Both paternal and maternal sides contribute. This highly polygenic nature means the paternal family history also matters significantly alongside the maternal line.
Women experience androgenetic alopecia differently. Instead of the Norwood recession pattern, women develop diffuse thinning across the crown (Ludwig scale). Oestrogen provides some protective effect, which is why pattern hair loss in women is rarer and typically starts later, often accelerating after menopause.
DHT binds to androgen receptors in sensitive follicles, causing them to gradually shrink over successive growth cycles. Follicles produce progressively finer, shorter hairs until they eventually stop producing visible hair. The 5-alpha reductase enzyme converts testosterone to DHT in the scalp.
The maternal side matters significantly but is not the whole picture. The AR (androgen receptor) gene on the X chromosome, inherited from mothers, makes the maternal grandfather a key predictor. However, over 280 variants across many chromosomes contribute to hair loss risk. Both paternal and maternal family histories are relevant for an accurate overall assessment.
Male pattern hair loss can begin as early as the late teens or early twenties, though it is most commonly noticed in the late twenties to thirties. Women with hereditary hair loss typically see it begin in the forties or fifties, often accelerating around menopause. The age of onset in close male relatives is often a useful indicator.
Hereditary hair loss cannot be fully prevented if you carry the genetic variants, but it can often be slowed. FDA-approved treatments include minoxidil (topical) and finasteride (oral, men only). Starting treatment early produces better outcomes. Hair transplants can restore coverage but do not address the underlying genetic sensitivity.
No. Stress-related hair loss (telogen effluvium) pushes follicles prematurely into the resting phase, causing temporary widespread shedding 2-3 months after the trigger. It typically recovers fully. Androgenetic alopecia is a progressive pattern driven by DHT sensitivity, not stress, though stress can accelerate it.