Male and female pattern hair loss: what is happening

Most hair loss in adults is not a sign that something is wrong with your health. It is pattern hair loss, known medically as androgenetic alopecia, and it is the most common reason both men and women thin over time.

Once you understand what is happening to the follicle itself, the treatment options stop being a list of random products and start to make sense.

What pattern hair loss actually is

Pattern hair loss is the gradual shrinking of hair follicles in the areas of the scalp that are sensitive to a hormone called dihydrotestosterone, or DHT. DHT is made from testosterone by an enzyme called 5-alpha-reductase. In follicles that are genetically primed to respond to it, DHT shortens the growing phase of each hair and shrinks the follicle a little more with every cycle. This process is called miniaturisation.

Over years, thick pigmented hairs are replaced by finer, shorter, paler ones, until some follicles stop producing a hair you can see at all. The hair is not really falling out faster. It is being replaced by something thinner each time it grows back.

How it looks in men

In men the pattern is familiar. The hairline recedes at the temples, the crown thins, and over time the two areas can meet. The back and sides are usually spared, because those follicles are not sensitive to DHT. That is why men keep a horseshoe of hair even when the top has gone, and it is also why hair transplants are possible.

Men can start to notice it in their twenties. By their fifties a majority have some degree of it. Doctors use the Norwood scale to describe how far it has progressed, from a slightly mature hairline through to extensive loss across the top.

How it looks in women

Female pattern hair loss looks different. The frontal hairline is usually kept, but the parting widens and the hair thins diffusely across the top of the scalp, often described as a Christmas-tree shape when you look down at the parting. Women very rarely lose hair in the way men do.

It becomes more common around and after the menopause, as falling oestrogen shifts the balance of hormones acting on the scalp. The Ludwig scale describes the stages. Because the thinning is spread out rather than focused on the hairline, it is easy to miss until a good deal of density has already gone.

Why it runs in families

The susceptibility is inherited from both sides of the family, not just from your mother's father as the old saying claims. Many genes are involved, which is why two brothers can lose hair at different rates and in different patterns.

What you inherit is how sensitive your follicles are to DHT, not a fixed fate. That distinction matters, because it is exactly why treatment that lowers DHT or supports the follicle can change the course of something that feels predetermined.

Why catching it early matters

Treatment is far better at keeping the hair you have than at regrowing hair from follicles that have already closed down. A miniaturised follicle can often be coaxed back into producing a thicker hair. A follicle that has been dormant for years usually cannot.

The practical message is simple. The earlier you act, the more there is to protect. Waiting to see how bad it gets is the one approach that reliably reduces what treatment can later do for you.

When it is not pattern hair loss

Not all thinning is androgenetic. Hair that comes out suddenly, in distinct patches, or alongside redness, scaling, scarring of the scalp, or symptoms such as tiredness or weight change, points to a different cause that needs looking into rather than a hair-loss prescription.

The next article in this series covers the reversible causes worth ruling out before you settle on pattern hair loss as the explanation.

The honest summary

Pattern hair loss is common, driven by DHT acting on genetically sensitive follicles, and it progresses slowly. It is treatable, and the treatments work best while there is still hair to protect. If you are noticing thinning and want to understand your own pattern and what can be done about it, a short assessment with one of our doctors is the place to start.

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If you want to move from reading to acting, the next step is a short, confidential assessment with one of our doctors.

Begin your assessment at this link. Online or in person at Westfield London.