Pattern loss
The most common cause by a wide margin. Follicles sensitive to androgens shorten their growing phase with each cycle, producing progressively finer hair until they stop. It is gradual, it follows a recognisable distribution, and it is the one where early intervention genuinely changes the outcome.
In men it recedes at the temples and thins at the crown. In women it widens the central part while preserving the frontal hairline. Same underlying process, different presentation.
Shedding — telogen effluvium
A shock pushes an unusually large cohort of follicles into the resting phase at once. Three months later they shed together. Childbirth, surgery, severe illness, crash dieting, a high fever and acute stress all do it.
The tell is timing and pattern: it starts abruptly about three months after the trigger, it is diffuse rather than patterned, and it usually recovers on its own once the cause has passed. The delay is why people so often blame the wrong month.
Deficiency and thyroid
Low ferritin and thyroid dysfunction both cause diffuse thinning and both are correctable, which makes them worth ruling out early. Heavy periods, restrictive diets and undiagnosed coeliac disease are the usual routes to low iron.
Normal blood results do not rule out pattern loss. They rule out one contributing cause. Plenty of people have both.
Tension and scarring
Traction alopecia comes from years of tight styling and shows along the hairline or wherever tension is applied. Caught early it recovers; once the follicle scars it does not.
Scarring alopecias are a different order of urgency. The follicle is destroyed and replaced with fibrous tissue, permanently. Signs worth acting on quickly: itching, burning, tenderness, redness, or smooth patches where the pore openings have disappeared.
Common questions
Can more than one cause be happening at once?
Frequently, and it is the main reason self-diagnosis goes wrong. Post-partum shedding on top of an underlying pattern loss is a common combination — the shedding resolves, the pattern loss does not, and the person concludes treatment failed.
How do I know which one I have?
History and pattern do most of the work. Sudden and diffuse points to shedding; gradual and patterned points to pattern loss; symptoms on the scalp itself point to something inflammatory that needs looking at promptly.
Is hair loss inherited from the mother’s side?
Not exclusively — that is a persistent myth. Androgen sensitivity is polygenic and inherited from both sides.
What an assessment establishes
- 1.Which process is causing the loss
Pattern loss, telogen effluvium, traction and scarring alopecia look similar in a mirror and behave nothing alike. The examination separates them, because the answer decides which routes are worth discussing at all.
- 2.Whether it is stable or still moving
Loss that is still progressing changes what any treatment can hold. It is the difference between planning around a fixed area and planning around one that will keep widening, and it is judged from history and examination rather than a single photograph.
- 3.Which routes are available to you, and which are not
Donor supply, scalp condition, skin type and how the loss is behaving each rule options in or out. You leave knowing what is on the table and what is not, without a price attached to the conversation.