Male pattern baldness: what it is and how to recognise it

Male pattern baldness, or male androgenetic alopecia, is the most common cause of hair loss in men. It often starts discreetly, with the temples rising or the crown thinning, and advances slowly over years. It is so common that many see it as inevitable, and it is true that it is not a dangerous condition. But it has a real impact on the self-esteem of many men, and today there are treatments with evidence that can halt progression in most cases, especially when started early.

It results from the action of dihydrotestosterone (DHT) on genetically sensitive follicles, which gradually shrink and produce ever finer hairs. It affects about half of white men at 50 and 80% at 70.

What male pattern baldness is

The role of DHT

Testosterone is converted into dihydrotestosterone (DHT) by an enzyme called 5-alpha-reductase, mainly type 2, present in the follicle. In the follicles at the top of the head in genetically predisposed men, DHT binds to androgen receptors and triggers a process of miniaturisation: the growth phase (anagen) becomes shorter, the follicle shrinks, and each new hair grows thinner and shorter, until it resembles an almost invisible fuzz.

It is not a question of having "too much testosterone". Most men with baldness have normal hormone levels. What differs is the sensitivity of the follicles, determined by genetics. That is why the follicles at the back and sides of the head, which are less sensitive to DHT, remain, and it is also why they can be used in hair transplants.

Genetics

Male baldness is strongly hereditary. The androgen receptor gene, on the X chromosome (inherited from the mother), plays an important role, but many other genes are involved, on several chromosomes, inherited from both parents. So the myth that it "comes from the maternal grandfather" is only part of the story. See Baldness and heredity: what is inherited and what is not.

How many men it affects

It is very common and increases with age. In white men, it is estimated that about 30% have some degree of baldness at 30, about 50% at 50 and about 80% at 70. It is less common and tends to be less extensive in men of Asian and African origin. It can start soon after puberty, and an early onset tends to be associated with more marked progression.

How to recognise it

The first signs

• The temples rise at the sides, forming a more marked "M". See Temples: natural or receding?.
• The crown gets thinner: the scalp shows more at the top of the back of the head, especially in overhead light or in photographs. See Thinning crown: when it is worth assessing.
• The forehead looks higher and the hairline less defined.
• The hairs in these areas are finer and shorter, and the hair loses volume and "holds" a style less well.
• More hairs on the pillow or in the shower, although many men notice the loss without noticing more shedding.

The sides and back of the head are spared. Progression is slow, over years, but may have phases of acceleration.

The Hamilton-Norwood scale

Created by Hamilton (1951) and revised by Norwood (1975), it is the scale used to classify male baldness:

There is also an "A" variant, in which the recession advances from front to back without a separate crown area. The scale helps to track progress and to plan treatments, including transplant.

Diffuse baldness

Some men have a less typical pattern: diffuse thinning on top, similar to that of women, without marked temple recession. It can be harder to recognise, and trichoscopy helps.

What can look like baldness and is not

How the diagnosis is made

In most men, the diagnosis is clinical: the history and pattern of loss are enough. The consultation includes:

• Clinical history: age of onset, progression, family history, medicines and supplements (including testosterone or anabolic steroids), illnesses, recent triggers.
• Examination: temples, crown, sides and back; beard and eyebrows; classification on the Norwood scale.
• Trichoscopy: shows the variability in hair thickness (more than 20% of thin hairs in the affected area is typical), follicular units with a single hair and discolouration around the follicles. It is especially useful in the early stages, in diffuse baldness and to document progress with images. See Trichoscopy: the examination that shows the scalp.
• Standardised photographs to compare over time.

Blood tests are not needed routinely in a man with the typical pattern. They are requested when there is diffuse hair loss, sudden onset, general symptoms, suspected deficiency or before some treatments. See Blood tests for hair loss: what to ask for.

Treatments with evidence

Male baldness is progressive. Treatments are more effective at halting progression than at recovering lost hair, results are assessed after 6 to 12 months and are only maintained while treatment continues. Not treating is also a legitimate choice. The decision is always individual and taken at a consultation.

Topical minoxidil

Approved for male baldness, as a solution or foam, usually at 5%. It prolongs the growth phase and increases the calibre of the hairs. In the first weeks there may be a temporary increase in shedding. The most common adverse effects are scalp irritation and itching and, rarely, hair in other areas.

Oral finasteride (1 mg)

It inhibits type 2 5-alpha-reductase and reduces DHT. It is the approved oral treatment for male baldness and is particularly effective on the crown. In long-term trials, with 1,553 men followed for up to five years, finasteride maintained lasting improvements, while in the placebo group the loss progressed (Kaufman, 2002).

• In May 2025, the pharmacovigilance committee of the European Medicines Agency (PRAC) concluded that suicidal thoughts are an adverse effect of oral finasteride, of unknown frequency, while maintaining that the benefits outweigh the risks for the approved indications (EMA, 2025). The 1 mg pack will now include a patient card. Anyone taking finasteride who notices mood changes, persistent sadness or thoughts of self-harm should stop the treatment and seek medical help. In a crisis, call SNS 24 (808 24 24 24) or 112.
• Finasteride roughly halves the PSA value; tell your doctor if you have prostate screening.
• Pregnant women or those who may become pregnant should not handle broken tablets.

For finasteride spray, applied to the scalp, the EMA found no link with suicidal thoughts.

Other treatments (outside approved indications or with more limited evidence)

• Low-dose oral minoxidil: used off-label, with promising results in recent studies; requires a prescription and monitoring (blood pressure, fluid retention, body hair).
• Dutasteride: inhibits both types of 5-alpha-reductase; approved for baldness in some Asian countries, but used off-label in Europe. The EMA added information on mood changes as a precaution.
• Platelet-rich plasma and low-level laser: some studies show modest benefit; heterogeneous protocols.
• Hair transplant: redistributes follicles from the back of the head, which are resistant to DHT, to the bald areas. It requires enough donor area and relatively stable baldness; it is usually combined with medical treatment to protect the hair that was not transplanted.
• Camouflage: hair micropigmentation, fibres, short cuts.

Be wary of shampoos, supplements or treatments that promise to "cure baldness" or guarantee results.

When you should ask for an assessment

At Luxmed, the hair medicine consultation includes a clinical history, examination, classification on the Norwood scale, trichoscopy with follow-up photographs and, when indicated, blood tests. The plan is agreed with you, with clear information about benefits and risks.

This article is for information purposes and does not replace a medical consultation. The results of any treatment vary from person to person.

Frequently asked questions