Dermatologist-written
condition guides.

Androgenetic alopecia (AGA) is the most common cause of hair loss worldwide - a genetically determined, hormone-dependent miniaturisation of hair follicles. In men it follows a predictable Norwood–Hamilton pattern; in women it presents as diffuse central thinning (Ludwig scale).

Telogen effluvium is a reactive, diffuse hair loss where a physiological or psychological shock forces a large percentage of anagen (growing) follicles into the telogen (resting) phase simultaneously. The result is a wave of shedding 2–3 months after the trigger event.

Alopecia areata is an autoimmune condition in which the immune system mistakenly attacks hair follicles, causing patchy, non-scarring hair loss. It can affect the scalp, beard, eyebrows, and body hair.

Traction alopecia results from chronic, repetitive tension on hair follicles - most commonly from tight hairstyles such as braids, ponytails, buns, extensions, or chemical relaxers combined with mechanical stress.

Seborrhoeic dermatitis is a chronic, relapsing inflammatory skin condition affecting sebaceous-gland-rich areas - primarily the scalp, face (nasolabial folds, eyebrows), and chest. It produces greasy flaking, erythema, and itch.

Scalp psoriasis is a chronic autoimmune skin condition characterised by thick, silvery, adherent plaques on the scalp. It affects up to 80% of patients with systemic plaque psoriasis and can occur in isolation.

Iron deficiency - even without overt anaemia - is one of the most common and correctable causes of diffuse hair shedding, particularly in women of reproductive age. Ferritin (iron storage) below 30–70 ng/mL impairs the hair follicle's rapid cell division.

Polycystic ovary syndrome (PCOS) is a common endocrine disorder in women of reproductive age, characterised by hyperandrogenism, ovulatory dysfunction, and polycystic ovaries. Elevated androgens drive both scalp hair miniaturisation (FPHL) and unwanted facial/body hair (hirsutism).

Hair breakage refers to fracture of the hair shaft mid-length rather than loss at the root. Frequent causes include chemical processing, heat styling, mechanical trauma, and nutritional deficiencies that weaken the cortex.