How to Tell If You Have Male Pattern Baldness: Early Signs & Norwood Stages

Spotting the Classic Pattern on the Hamilton-Norwood Scale

Affecting roughly half of men by age 50—and frequently beginning in your 20s or 30s—androgenetic alopecia progresses gradually rather than overnight. Clinicians map this progression using the Norwood scale:

1. Stages 1–2: Minimal recession or subtle triangular thinning at the frontotemporal corners (maturing hairline).
2. Stage 3: Distinct ‘M’, ‘U’, or ‘V’ temple recession—or early thinning appearing at the vertex (crown).
3. Stages 4–5: Deeper frontal recession accompanied by a widening crown spot, separated by a thinning bridge of hair across the mid-scalp.
4. Stages 6–7: Temple and crown zones merge across the top of the scalp, leaving a horseshoe band of DHT-resistant follicles around the sides and back.

Why DHT Shrinks Follicles—and How to Rule Out Other Causes

Genetics account for roughly 80% of susceptibility—inherited from either your mother’s or father’s side. In genetically sensitive scalp follicles, the enzyme 5-alpha-reductase converts testosterone into dihydrotestosterone (DHT), which binds follicular androgen receptors and progressively shrinks (miniaturizes) each new hair shaft.

Before assuming permanent pattern baldness, consider reversible mimics:

• Telogen effluvium: Diffuse, all-over shedding 2–3 months after high fever, major stress, surgery, or rapid weight loss.
• Alopecia areata: Sudden, smooth coin-shaped bald patches driven by autoimmune activity, sometimes affecting the beard or eyebrows.
• Nutritional or thyroid triggers: Iron, ferritin, vitamin D, or thyroid imbalances that cause generalized thinning.

Clinically Proven Treatments That Preserve Your Hairline

Because miniaturized follicles remain alive long before going dormant, early intervention delivers the strongest preservation and regrowth:

• Minoxidil (5% topical foam/solution or low-dose oral tablet): Increases microvascular blood flow and extends the anagen growth phase.
• Finasteride (1 mg daily): Inhibits type II 5-alpha-reductase, lowering scalp DHT by ~60–70% to halt miniaturization.
• Dutasteride (0.5 mg daily, off-label): Blocks both type I and II 5-alpha-reductase isoenzymes for men needing stronger DHT suppression under medical supervision.