What Causes Male Pattern Baldness

Male pattern baldness affects a large proportion of men, yet it’s surrounded by myths. Understanding what actually causes it — and what doesn’t — is the key to deciding whether and how to treat it.

What is male pattern baldness?

Male pattern baldness, known medically as androgenetic alopecia, is by far the most common cause of hair loss in men. It follows a recognisable pattern: a receding hairline (often starting at the temples), thinning at the crown, and over time these areas may merge, leaving hair around the sides and back. It’s a gradual, progressive process driven by a combination of genetics and hormones, not by anything you’ve done wrong. It’s extremely common — affecting many men by their thirties and the majority by later life — and while it’s harmless to your physical health, it can affect confidence and wellbeing, which is a perfectly valid reason to seek treatment. The encouraging news is that we understand the mechanism well, and there are evidence-based treatments that can slow the process and regrow some hair, particularly when started early. Understanding the cause helps explain why those treatments work.

The role of DHT

The central player in male pattern baldness is a hormone called dihydrotestosterone (DHT). DHT is produced from testosterone by an enzyme called 5-alpha-reductase. In men with a genetic predisposition, the hair follicles on the top and front of the scalp are sensitive to DHT. When DHT binds to these follicles, it causes them to miniaturise — shrinking over successive growth cycles so they produce progressively finer, shorter, lighter hairs, until eventually they may stop producing visible hair altogether.

Crucially, the follicles at the back and sides of the scalp are genetically resistant to DHT, which is why hair there usually persists — and why it’s used for hair transplants. This DHT mechanism is the reason a treatment like finasteride, which reduces DHT, can slow or partly reverse the process.

Genetics: it’s not just your mother’s side

A persistent myth is that baldness is inherited solely from your mother’s father. In reality, the genetics are complex and come from both sides of the family. Multiple genes are involved, which is why the age of onset, pattern and speed vary so much between individuals — even between brothers. If close male relatives have male pattern baldness, your likelihood is higher, but it’s not guaranteed, and the way it progresses is individual.

How to recognise it

Typical signs of male pattern baldness include:

• A receding hairline, often forming an “M” shape at the temples
• Thinning at the crown (the top-back of the head)
• Hair becoming finer and shorter in affected areas over time
• A pattern that develops gradually over months and years

If hair loss is sudden, patchy, or comes with scalp symptoms like redness, scaling or itching, that suggests a different cause — such as alopecia areata, a fungal infection or telogen effluvium — and is worth getting checked.

What doesn’t cause male pattern baldness

Plenty of myths deserve busting:

• Wearing hats doesn’t cause it
• Frequent washing or normal shampooing doesn’t cause it
• Everyday stress doesn’t cause male pattern baldness (though severe stress or illness can trigger temporary shedding called telogen effluvium)
• Poor circulation from “not enough blood to the scalp” isn’t the cause

Recognising what isn’t to blame helps you focus on treatments that actually target the real mechanism.

What can be done about it?

Male pattern baldness can’t be cured, but it can be managed effectively, especially if you act early while follicles are still active. The two treatments with the strongest evidence, recognised by the British Association of Dermatologists, are:

• Finasteride — a daily tablet that lowers DHT, tackling the root cause. See our guide to finasteride side effects.
• Minoxidil — a topical solution or foam that prolongs the hair growth phase and improves follicle activity.

They can be used together for a greater effect, and both need to be continued to maintain results.

Getting evidence-based treatment

If you’ve noticed thinning and want to do something about it, the most effective time to act is early. You can start with a confidential hair loss treatment online uk consultation, where a prescriber assesses your hair loss and recommends a suitable plan, or visit our Sheffield hair loss clinic for a face-to-face scalp assessment. We give honest, evidence-based advice — no miracle cures — so you can make an informed decision about your hair.