In short: male pattern baldness (androgenetic alopecia) is the most common cause of hair loss in men. It's genetic and driven by the hormone DHT, which gradually shrinks follicles at the hairline and crown. It follows predictable stages (the Norwood scale). It can't be cured, but minoxidil and finasteride can stop or slow it in most men, and they work best when started early.
Why it happens
- Follicles on the top and front of the scalp in some men are genetically sensitive to DHT (dihydrotestosterone, made from testosterone).
- DHT causes miniaturisation: each growth cycle, the hair comes back thinner and shorter, until the follicle stops producing visible hair.
- Hair at the sides and back is usually resistant, which is why transplants use it.
- Testosterone levels are usually normal. It's the follicles' sensitivity that differs.
Genes come from both sides of the family. The "it's from your mother's father" idea is only partly true: one important gene is on the X chromosome (inherited from your mother), but many other genes are involved.
The stages (Norwood scale)
| Stage | What you see |
|---|---|
| 1 | No real recession |
| 2 | Slight recession at the temples ("mature hairline" range) |
| 3 | Deeper "M"-shaped temple recession; the first clearly balding stage |
| 3 vertex | Stage 2–3 hairline + thinning on the crown |
| 4 | Deeper front recession + a crown bald spot, separated by a band of hair |
| 5 | Larger front and crown areas; the band between them thins |
| 6 | The band is gone; front and crown merge |
| 7 | Only a horseshoe of hair at the sides and back |
Not sure of your stage? → Hair loss stage checker
How it's diagnosed
Usually by a dermatologist looking at your scalp, often with a dermatoscope that shows miniaturised hairs. Blood tests aren't usually needed unless the pattern is unusual or there are other symptoms.
Rule out look-alikes: sudden all-over shedding (telogen effluvium), round patches (alopecia areata), and itchy, flaky scalp (dandruff).
Treatment by stage
| Stage | Common approach |
|---|---|
| 1–2 (worried, or a strong family history) | Monthly photos; consider starting treatment if you see change |
| 2–4 | Finasteride and/or minoxidil: the best time to start |
| 3 vertex–5 | Both medicines; consider PRP as an add-on; transplant if stable and suitable |
| 5–7 | Medicines to protect the remaining hair; transplant if there's enough donor hair; or embrace a short cut or shaved look |
Compare options: Minoxidil vs finasteride · Finasteride vs dutasteride · Oral vs topical minoxidil
Hair transplant
A transplant moves DHT-resistant follicles from the back of the head to the bald areas. It works well for suitable men, but it doesn't stop the remaining hair from thinning, so most surgeons recommend medicines too. → Hair transplant guide (coming in phase 2): Costs and clinics
Myths
- Caps and helmets cause baldness: no. (Very tight headgear rubbing daily can cause breakage, but not pattern baldness.)
- Washing hair often causes baldness: no.
- Oils, onion juice or shampoos can reverse it: no good evidence. → Minoxidil vs natural alternatives
- High testosterone means you'll go bald: not necessarily. Follicle sensitivity matters more.
- Masturbation causes hair loss: no evidence.
See a doctor soon if you have: round bald patches that appear suddenly · hair coming out in clumps · redness, pain, pus, scaling or scarring on the scalp · hair loss with fever, weight loss, irregular periods, acne or new facial hair · eyebrow or eyelash loss · hair loss in a child.
Sources
- Norwood OT. Male pattern baldness: classification and incidence. South Med J. 1975;68:1359–65.
- Kaufman KD, et al. J Am Acad Dermatol. 1998;39:578–89.
- Gupta AK, et al. JAMA Dermatol. 2022;158(3):266–74.
Medical review pending: not yet reviewed by a dermatologist. Medical disclaimer
Discussion
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