5-alpha reductase is the enzyme that converts testosterone to DHT; some medicines block it.
A chronic scarring folliculitis affecting the nape and occipital scalp.
An autoimmune, non-scarring hair loss condition that often causes round or oval patches.
Alopecia areata affecting the beard area.
Severe forms of alopecia areata causing complete scalp hair loss or complete body hair loss.
Hair loss triggered or worsened by anabolic-androgenic steroids in genetically susceptible people.
Rapid hair loss caused by damage to actively growing hairs, classically during chemotherapy.
A common, progressive, non-scarring patterned hair loss driven by genetic susceptibility and androgen biology.
A pattern hair loss classification system designed for both men and women.
An anti-androgen sometimes used off-label for female pattern hair loss under specialist care.
Biotin can help true biotin deficiency, but it is not proven to treat ordinary pattern hair loss.
Pigmented broken hairs at scalp level, often indicating active follicular damage or breakage.
A scarring alopecia that usually begins at the crown and spreads outwards.
Hair loss caused by cancer treatments that affect rapidly dividing hair follicle cells.
Persistent diffuse shedding lasting more than six months, often with no single obvious trigger.
A stable, non-scarring patch of hair loss, usually on the frontotemporal scalp.
A specialist alopecia areata treatment that creates controlled allergic inflammation on the scalp.
Diffuse shedding after rapid weight loss, severe calorie restriction or inadequate nutrition.
An anti-androgen used in selected women with pattern hair loss, especially where hyperandrogenism is relevant.
Alopecia areata presenting as widespread shedding rather than obvious round patches.
Generalised reduction in scalp hair density rather than one sharply defined bald patch.
A potent androgen made from testosterone and strongly linked to male pattern hair loss.
Scarring hair loss caused by discoid lupus affecting the scalp.
An inflammatory scalp condition causing painful nodules, abscesses and scarring hair loss.
A topical irritant sometimes used to stimulate regrowth in alopecia areata.
Hair shedding or thinning triggered by a medicine or drug exposure.
A stronger dual 5-alpha reductase inhibitor that reduces DHT more profoundly than finasteride.
Pattern-like thinning or shedding associated with anti-oestrogen or hormone-modifying treatments.
Short tapered hairs that can be seen at the edge of alopecia areata patches.
An experimental regenerative treatment using extracellular vesicles that may influence hair follicle signalling.
A common type of non-scarring hair loss in women, usually causing central scalp thinning with a retained frontal hairline.
A 5-alpha reductase inhibitor used for male pattern hair loss to reduce DHT.
Recognised potential side effects include sexual dysfunction and mood-related symptoms.
A natural grouping of one to four hairs that emerges from the scalp as a unit.
A scarring alopecia that causes progressive recession of the frontal hairline and often eyebrow loss.
The thickness or diameter of an individual hair shaft.
The number of hairs in a defined scalp area.
Electrostatic cosmetic fibres used to make existing hair look thicker.
The repeating cycle of hair growth, transition, rest and shedding.
The surgical planning of a natural-looking frontal hairline in hair transplantation.
Alopecia means hair loss. It can be temporary or permanent, and scarring or non-scarring.
The process where thick terminal hairs become progressively finer, shorter and lighter.
A simple test where a small group of hairs is gently pulled to assess active shedding.
Variation in hair thickness across the scalp, often used as a trichoscopic clue to pattern hair loss.
An increase in hairs falling out, often noticed in the shower, brush, pillow or hands.
FUE removes follicular units one by one; FUT/FUSS removes a strip that is dissected into follicular units.
Temporary shedding of existing or transplanted hairs after hair restoration surgery.
Steroid injections into bald patches, commonly used for limited alopecia areata.
Diffuse shedding may be associated with low iron stores, but the relationship is not straightforward.
An antifungal shampoo used for dandruff and seborrhoeic dermatitis, sometimes as an adjunct in pattern hair loss.
A scarring inflammatory alopecia that can cause patchy permanent hair loss.
A condition where growing hairs are poorly anchored and can be pulled out easily.
A light-based treatment using low-energy red or near-infrared light to stimulate hair follicles.
A three-grade scale used to describe female pattern hair loss over the crown.
Loss of eyebrow or eyelash hair.
Pattern hair loss in men, usually involving a receding hairline, temple recession and/or crown thinning.
Hair thinning around or after menopause, often involving female pattern hair loss or increased shedding.
Controlled tiny needle injuries to the scalp, usually used as an adjunct to stimulate repair pathways.
A foam formulation of topical minoxidil used for pattern hair loss.
A person who does not get meaningful improvement from minoxidil despite correct, consistent use.
Temporary early hair fall that can occur after starting minoxidil.
A visual grading system for male pattern hair loss severity.
A female pattern hair loss pattern with widening over the central frontal scalp.
A band-like form of alopecia areata around the sides and back of the scalp.
Low-dose tablet minoxidil used off-label for hair loss under medical supervision.
A subtle brown halo around hair follicles on trichoscopy, often discussed in androgenetic alopecia.
Digital methods for measuring hair density, diameter and growth-cycle features in a target scalp area.
A blood-derived injectable treatment related to PRP, designed to release growth factors gradually.
A procedure where concentrated platelets from the patient’s own blood are injected into the scalp.
A debated term for persistent sexual, physical or psychological symptoms reported after finasteride.
Increased shedding after giving birth, usually due to a temporary shift in the hair cycle.
A rare form of patchy permanent scalp hair loss, usually diagnosed after excluding other scarring alopecias.
Backward movement of the frontal hairline, especially at the temples.
An oral JAK3/TEC inhibitor licensed for severe alopecia areata in people aged 12 and over.
The part of the donor scalp most likely to retain hair long term and provide transplantable grafts.
The Severity of Alopecia Tool score estimates the percentage of scalp hair loss in alopecia areata.
A small sample of scalp skin examined under a microscope to clarify uncertain hair loss diagnoses.
Inflammation of scalp hair follicles, often causing itchy or sore bumps and pustules.
A tattoo-like technique that places pigment dots on the scalp to mimic shaved hair or reduce contrast.
A group of hair loss disorders where inflammation destroys follicles and can cause permanent loss.
A five-point photographic scale for grading female pattern hair loss by midline part width.
An antiandrogen medicine used off-label for some women with female pattern hair loss.
Consistent clinical photographs used to track hair loss or treatment response over time.
A common search term for temporary shedding after significant physical or emotional stress.
A temporary, non-scarring shedding condition caused by many hairs entering the resting phase together.
Diffuse shedding or thinning associated with an underactive or overactive thyroid.
A fungal infection of the scalp and hair, also called scalp ringworm.
Steroid creams, lotions, gels or foams applied to inflammatory hair loss areas.
Local scalp delivery of dutasteride, usually topical or injection-based, with limited standardisation.
Finasteride applied to the scalp to reduce local DHT with lower systemic exposure than tablets.
A scalp-applied hair growth stimulant used for male and female pattern hair loss.
Hair loss caused by repeated tension on the hair from styling, extensions or tight hairstyles.
A hair shaft defect where hairs fracture at weak points, causing breakage and fraying.
Magnified examination of the scalp and hair using a dermatoscope or digital device.
Hair loss caused by recurrent pulling of one’s own hair.
A fine, short, lightly pigmented hair.
Low vitamin D may be relevant in some hair loss presentations, but it is not a stand-alone diagnosis.
A method of counting hairs shed during washing to help evaluate excessive shedding.
Non-surgical hair replacement options used to cover extensive or treatment-resistant hair loss.
Yellow follicular dots seen on trichoscopy in several hair loss conditions.
