Male pattern baldness, known clinically as androgenetic alopecia, is a genetically influenced pattern of hair thinning driven by hair follicles’ sensitivity to hormones over time. It typically starts at the temples or crown and follows a fairly predictable pattern, though the pace and extent vary enormously from person to person. It is not an illness, and it is not caused by anything the person did wrong. Understanding the general pattern can help someone recognise what they’re seeing, even though no article can tell an individual what their own timeline will look like.
This piece explains the mechanics of male pattern baldness in general terms — what’s happening at the follicle level, how the recognised stages are usually described, and what distinguishes ordinary pattern thinning from hair loss that warrants medical attention. It does not offer a diagnosis or a plan for any individual reader, and it doesn’t promise what treatment, if any, will do for anyone’s hair.
What is happening at the follicle level
Male pattern baldness is linked to how certain hair follicles respond to androgens, a class of hormones that includes testosterone and its derivative, dihydrotestosterone (DHT). In follicles that are genetically sensitive to DHT, exposure over years is thought to gradually shorten the growth phase of the hair cycle and shrink the follicle itself, a process sometimes called miniaturisation. Over successive cycles, hairs from affected follicles grow back finer, shorter and lighter until, in some follicles, growth stops altogether.
This is different from the kind of daily shedding everyone experiences as hair naturally cycles through growth and rest. If you’re trying to work out whether what you’re seeing is ordinary turnover or a pattern starting to establish itself, it can help to read about the difference between normal shedding and progressive thinning before assuming either one.
Where it usually starts and how it tends to spread
In most cases, pattern hair loss follows one of two starting points, sometimes combined: a receding hairline at the temples, forming an M-shape, or thinning at the crown (vertex), often first noticed by someone else or in photos taken from behind. Over time, these two areas can expand and, in some people, eventually meet, leaving a horseshoe-shaped band of hair around the sides and back — areas that tend to be far less sensitive to DHT and are usually the last to be affected, if they’re affected at all.
The most commonly referenced way of describing this progression is the Norwood scale, a set of illustrated stages running roughly from a full hairline (Norwood 1) to extensive baldness across the top of the scalp (Norwood 6–7). It’s worth being clear about what this scale is and isn’t: it’s a descriptive tool used to talk about degree of progression, not a countdown clock. Someone can stay at an early stage for decades, and there’s no way for a scale, or a website, to predict how quickly — or whether — a particular person will move through it.
| General stage | What it typically looks like |
|---|---|
| Early | Slight recession at the temples, or a hairline that looks less straight than before |
| Moderate | More defined temple recession and/or visible thinning at the crown |
| Advanced | Temple and crown areas enlarging, sometimes starting to connect |
| Extensive | Little hair remains on top, with a band of hair persisting at the sides and back |
Why the pattern and pace differ so much between people
Genetics play a large role, involving multiple genes rather than a single inherited trait, which is part of why patterns don’t map neatly from father to son. Age matters too — pattern hair loss becomes more common the older a person gets, though it can begin in the twenties or even earlier for some. Hormonal factors, general health, and certain medications can also influence the picture, which is one reason two people who appear to be at a similar stage can have very different experiences of how it started and how it’s changing.
Because so many variables are involved, nobody can look at a photo or a short description and tell someone what stage they’ll reach or how fast they’ll get there. Genuine assessment of an individual’s pattern and options is a conversation to have with a doctor, dermatologist or another qualified prescriber — not something a general information site can substitute for.
What this is not: red flags that need medical attention
Pattern baldness is gradual and follows the general shapes described above. Some kinds of hair loss look different, and those differences matter. Sudden hair loss, hair loss in distinct round or irregular patches rather than an overall thinning pattern, hair loss in a child, or a scalp that is painful, scaly, shiny or scarred alongside the shedding are all reasons to see a doctor rather than keep reading articles online. The same goes for hair loss that comes with other unexplained symptoms elsewhere in the body.
This distinction isn’t just about getting the right label. Some causes of hair loss — including certain scarring conditions — can permanently damage the follicle if left unassessed, meaning the window for any kind of intervention narrows the longer it’s left. Ordinary pattern thinning doesn’t carry that particular urgency, but the red-flag list above does, and it’s worth taking seriously.
What people generally do once they notice a pattern
Once someone recognises they may be dealing with pattern hair loss, the paths people take vary widely, and there isn’t a single correct one. Some choose to look into the more established treatment categories, including topical options and a prescription-only oral medication that a doctor can discuss in detail — an approach explored in more general terms in an overview of treatment categories for hair loss. Others look into hairstyling, haircuts and scalp care that work with a changing hairline rather than against it. Others decide, reasonably, to do nothing at all and let the pattern run its course; that is a legitimate outcome, not a failure of willpower or self-care.
Whatever direction someone leans, it helps to go in with realistic expectations: no shampoo, supplement, device or medication can be guaranteed to regrow hair, stop a pattern in its tracks, or work the same way for everyone, because outcomes depend on genetics, hormones, age and general health in ways that can’t be predicted from a website. Anyone considering a prescription-only option should raise it directly with a prescriber, who can talk through what’s realistic given their particular situation, not a general audience.
Frequently asked questions about male pattern baldness
What age does male pattern baldness usually start?
It can begin any time after puberty, though it becomes more common with age. Some people notice early signs in their twenties, others not until much later, and some never develop a noticeable pattern at all — there’s no fixed starting age.
Is male pattern baldness genetic from the mother’s or father’s side?
Both sides contribute. It’s influenced by multiple genes rather than one, so looking only at a father’s hairline, or only at a mother’s family, doesn’t reliably predict what will happen to any individual.
Can male pattern baldness be stopped completely?
No treatment can promise to halt it entirely for everyone, since progression depends on genetics, hormones and other individual factors. A doctor or prescriber can discuss recognised options and realistic expectations for a specific situation.
How do I know if it’s pattern baldness or something else?
Pattern baldness is usually gradual and follows recognisable shapes at the temples and crown. Sudden loss, patchy bald spots, or a scalp that’s painful, scaly or scarred point to a different cause and are reasons to see a doctor.
Does wearing hats or using certain shampoos cause male pattern baldness?
No — pattern baldness is driven by genetics and hormone sensitivity in the follicles, not by hats, shampoo choice, or hairstyling habits. Those things may affect hair’s appearance or condition but aren’t established causes of the pattern itself.
Keep reading
Scarring Alopecia: Why Early Assessment Matters, Traction Alopecia: How Tight Hairstyles Cause Hair Loss, The Norwood Scale: How Male Hair Loss Is Measured, Alopecia Areata: What Causes Patchy Hair Loss.
Balds publishes general educational information about hair loss, not medical advice. We are writers, not doctors or dermatologists. If your hair loss is sudden, patchy, painful, or comes with other unexplained symptoms, see a doctor or a dermatologist — some forms of hair loss can become permanent without early assessment.