Hamilton–Norwood Scale

Discover the scale that measures the level of male pattern baldness

Determining the degree of alopecia can be difficult, especially since everyone can experience different hair loss problems. At Hair Center Mexico, thanks to the Hamilton-Norwood scale and our experienced hair transplant surgeons, we can help you to understand your current degree of alopecia in order to offer you the best and most reliable diagnosis.

The Hamilton-Norwood scale is very useful during the process of choosing the ideal treatment for each patient, whether it is a preventive therapy, such as the well-known platelet-rich plasma injection treatment, or hair transplants including the latest and famous follicular unit extraction (FUE). But what is this scale all about?

What is the Hamilton-Norwood scale?

In a few words, the Hamilton-Norwood scale is the most common classification system used to diagnose and measure the diverse degrees of androgenetic alopecia in men. It consists of two studies conducted by the anatomist James Hamilton and O. Norwood, dermatologist and hair transplant surgeon. The first scale was introduced by Hamilton in 1951, and years later improved by Norwood, who took the original study to provide a detailed classification of each hair loss stage.

The Hamilton-Norwood scale includes the 7 major stages of hair loss that can be found in male-pattern baldness (MPB). The scale also includes various subsets known as A and V variants. In the type A variant, the hair loss problem is concentrated in the frontotemporal hairline area, while type V variant includes the crown as well.


Stages of hair loss

According to the Hamilton-Norwood scale, a large number of patients suffering from male pattern baldness may experience all 7 stages over time.

» Stages 1-2
Minimal or no recession of the hairline

Some experts attribute these stages more to one of the consequences of aging than to a real baldness problem. According to the Hamilton-Norwood scale, stage 2 is known as the beginning of hair loss. Both are the earliest stages of baldness, usually characterized by a smooth, symmetrical hairline recession. In these degrees, the hairline begins to slightly recede, however, it is almost imperceptible. These are stages which almost all men will go through and it is quite probable the problem won't advance any further or alopecia’s evolution will be very slow.

» Stages 3-3V
Hair loss is more visible

The minimal extent of hair loss is enough to be defined as a baldness problem. Here men usually start considering to do their research about hair treatments and to look for specialist advice. Androgenic alopecia is more noticeable, as the patient begins to experience a more frequent hair loss in the frontal hairline. However, the hair loss problem at stage 3V starts to affect the vertex (or crown) and usually gets worse over time, while the hairline recession stays at stage 2.

» Stage 4
Chronic alopecia

At this point on the scale, the so-called chronic alopecia breaks out. Hair volume decreases up to 70% and baldness in the hairline and vertex are clearly more visible. The recession at the temples is more pronounced and there is sparse hair or no hair in the crown at all. This hair loss pattern is separated by a band of hair that connects with the sides of the scalp and forms a deeper M-shape.

» Stage 5-5A-5V
Minimal hair density

The sparse band of hair that separates the crown and the frontotemporal areas begin to disappear and the hair loss areas are larger than in stage 4. A small patch at the front of the scalp might be present in both stages 5 and 5V, contrary to the stage 5A where that patch is completely gone.

» Stage 6
The front hair patch is gone

At stage 6, the bridge of hair dividing the vertex and the hairline is almost gone and the little patch of hair at the front of the scalp has completely disappeared. The extent of hair loss is greater as the hair loss areas at the temples are now connected to the balding area in the crown.

» Stage 7
The most severe stage of hair loss

This is considered the most severe stage of male-pattern baldness. Stage 7 is distinguished by the complete loss of hair at the top of the scalp and the hairline. The little existent hair is usually not dense and probably very thin, and there is just a strip of hair that goes around the sides of the head.

Get your online consultation

Remember that a healthcare professional is the only one who can provide you with an accurate diagnosis and determine your stage of male-pattern baldness. Get your online consultation at Hair Center Mexico and make the choice of restoring not only your hair but your confidence!


How long do hair transplants last?

For most patients, hair transplant should last a lifetime.

How much time off from work do I need for having FUE Hair transplant in Mexico?

We recommend taking two days off. Treatment can take a several hours, depending on the quantity of hair needed. We recommend our patients to consider two days depending on type of work they have, but some patients are able to return to the next day.

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