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Hair restoration terminology, plainly.

The technical terms patients actually encounter — in plain language, with cross-links to the relevant articles. From anagen to vellus, all the vocabulary you’ll need to read the literature or hold a real conversation in consultation.

Reviewed by Dr. Robert Jones
30 terms · expanding
CHAPTER IThe Vocabulary

Alphabetical. In plain language.

ABHRS

American Board of Hair Restoration Surgery. Diplomate certification — the field-specific board credential indicating specialised training and continuing education in hair restoration.

Alopecia

Medical term for hair loss of any cause — androgenetic alopecia (pattern), alopecia areata (autoimmune), telogen effluvium (shedding), scarring alopecias, and more.

Anagen

The active growth phase of the hair cycle. Each follicle stays in anagen for 2–7 years (genetically determined), producing a continuously growing hair shaft.

Androgen

Male sex hormones, including testosterone and dihydrotestosterone (DHT). Drives male pattern hair loss in genetically susceptible men.

Androgenetic Alopecia

Pattern hair loss driven by androgens (DHT) acting on genetically susceptible follicles. The most common cause of hair loss in men and women.

Catagen

The brief 2–3 week transition phase between anagen (growth) and telogen (rest). About 1% of follicles are in catagen at any given time.

CPSO

College of Physicians and Surgeons of Ontario — the regulatory body that licenses every physician in Ontario. Dr. Jones is registered #31693.

DHT (Dihydrotestosterone)

Derivative of testosterone (via 5-alpha-reductase) that miniaturises hair follicles in genetically susceptible scalp areas. Cause of male pattern hair loss.

Donor Area

The back and sides of the scalp where DHT-resistant follicles are harvested for transplantation. The donor area is finite — what's there is what's available, for life.

Finasteride

Oral medication (1mg/day) that inhibits 5-alpha-reductase, dropping scalp DHT by ~70%. Most-studied medical therapy for male pattern hair loss.

FISHRS

Fellow of the International Society of Hair Restoration Surgery. Senior credential awarded for sustained contribution to the field. Dr. Jones holds FISHRS since 2015.

Follicle

The skin structure that produces hair. Each follicle cycles through anagen (growth), catagen (transition), and telogen (rest) phases independently.

Follicular Unit

Naturally occurring grouping of 1–4 hairs that emerge from the same skin opening. The transplant unit in modern hair restoration.

FUE

Follicular Unit Extraction. Surgical technique where each follicular unit is extracted individually using a small punch. Scar-free, surgeon-led.

FUT

Follicular Unit Transplantation (strip surgery). Donor strip is removed and dissected into follicular units under microscope. Higher single-session yield than FUE; leaves a thin linear scar.

Graft

A follicular unit prepared for transplantation. A typical hair restoration session uses 1,500–4,500 grafts.

Hairline Design

Hand-drawn pattern of where transplanted hair will be placed at the front of the scalp. The most artistic step in the procedure and the most permanent decision.

ISHRS

International Society of Hair Restoration Surgery. The field's primary professional society. Dr. Jones has been a member since 1996, FISHRS since 2015.

Ludwig Scale

Classification system for female pattern hair loss — three stages describing diffuse thinning across the top of the scalp with preserved frontal hairline.

Miniaturisation

Progressive thinning and shortening of hair follicles in androgen-susceptible scalp regions. The biological mechanism of pattern hair loss.

Minoxidil

Topical or oral medication that prolongs the anagen phase and increases blood flow to follicles. FDA-approved for hair growth; works alongside finasteride.

Norwood Scale

Classification system for male pattern hair loss — seven stages from minimal recession (I) to most advanced (VII). The clinical standard.

PRP

Platelet-rich plasma. Patient's own blood, concentrated and reinjected into the scalp to stimulate dormant follicles. Modest evidence; works best as an adjunct.

Recipient Site

The thinning or balding scalp area where transplanted grafts are placed. Created by the surgeon at specific angles, depths, and densities before implantation.

RealSelf

Independent third-party patient review platform. Dr. Jones's RealSelf profile holds 146 photos, 36 reviews averaging 4.8 / 5, and 201 patient questions answered.

SMP

Scalp Micropigmentation. Tattoo-style pigment deposited in the scalp to mimic the appearance of stubble or hair density. Useful for advanced loss or scar camouflage.

Telogen

The resting phase of the hair cycle. Follicle is dormant for ~3 months before shedding the existing hair shaft and beginning a new growth cycle.

Telogen Effluvium

Synchronised shedding event triggered by stress, illness, hormonal shift, or medication. Almost always temporary; resolves on its own within 12 months.

Trichology

Specialised study of hair and scalp conditions. Trichologists provide diagnostic and therapeutic services for non-surgical hair concerns.

Vellus Hair

Fine, short, often unpigmented hair — the type that miniaturised follicles produce in late-stage pattern hair loss before stopping production entirely.

Read the related articles

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