The Norwood scale explained: all stages of hereditary hair loss

The Norwood scale sorts male hereditary hair loss into one of twelve graded patterns on the scale, from a still-full hairline to a narrow ring of hair at the back of the head.¹ Seven basic stages represent the extent, plus finer gradations for particular courses. Doctors use it to classify a loss pattern consistently, and it lets you place yourself roughly.

One important thing first: the scale records how your pattern looks right now. It does not predict how far your hair loss will go, or how fast. It is a snapshot, not a forecast. What drives hereditary hair loss and why it affects mainly the forehead and crown is covered under Understanding hair loss.

What the Norwood scale is and what it is for

The full name is the Hamilton-Norwood scale, after the two doctors who developed and later revised it. It is the common classification for androgenetic (hereditary) hair loss in men. Instead of vaguely saying „pretty thin already“, the finding is assigned to a numbered stage.

This has a practical use. A stage captures the current pattern and its extent in one word that means the same to everyone. Doctors base their assessment and their treatment decision on it, and over time it becomes possible to compare whether a pattern stays stable or progresses further.² For you, the scale mainly helps to put into words where you stand right now.

It is made up of seven basic stages for the extent, plus a separate form with additional thinning at the crown and the four type A variants for a differing course. Together these make up the twelve illustrations of the classic classification, which the next sections go through one by one.¹

The Norwood scale is tailored to the male pattern. In women, hereditary hair loss looks different, and there is a separate classification for it. More on that below.

The regular stages from I to VII

The regular series describes the most common course, in which two zones are affected one after the other: first the hairline recedes at the forehead, and only in the higher grades does a thinning spot on the crown join it. In the highest grades the two merge. Within grade III, a further distinction is made between a form with and one without thinning at the crown.

• I: No or barely visible recession. The hairline still sits where it did in younger years.
• II: The hairline recedes slightly at the temples, usually symmetrically. These are the beginnings of a receding temple line, often described as an M shape.
• III: The receding temples are cut in more deeply and clearly pronounced. This is the extent usually regarded as the onset of balding.
• III vertex: The receding temples stay at about the level of grade III, and in addition the crown begins to thin. Vertex is the technical term for the crown area, that is, the bald spot at the back of the head.
• IV: The receding temples and the thinning at the crown are both more pronounced. A band of denser hair still stands between the forehead and the crown.
• V: The front zone and the crown grow larger, and the separating band of hair between them becomes narrower and thinner.
• VI: The separating band largely disappears, and the two bald areas merge into one another.
• VII: The most pronounced form. No hair grows on the crown any more; all that remains is a narrow band at the sides and the back of the head, often described as a horseshoe.¹

The stages are reference points on a sliding course, not sharply separated boxes. Many men fall between two stages or do not fit exactly into one. That is normal and no contradiction of the scale.

The type A variants: when the front recedes as a whole

Alongside the regular series, the scale recognises a second pattern, the type A variants. They are not merely an intermediate stage but a course of their own. The difference lies in how the hair recedes. In the usual course this happens at two places at once, at the temples and at the crown. In the type A variant, the hairline instead recedes in a single wave from front to back.¹

Two things are missing here: no separate bald spot forms at the crown, and no island of denser hair remains in the middle between the forehead and the crown. The head thins evenly from the front, rather than at two separate places.

The type A variants carry an „a“ after the numeral and are graded by the extent of the receding area: IIa, IIIa, IVa and Va. This series goes no further than Va; there is no „VIa“ or „VIIa“. Overall, type A courses usually remain less extensive than the highest grades of the regular series, but the evenly receding front often makes them noticeable early on.¹

How do I place my stage roughly?

The easiest way is with two photos in good light: one from the front of the hairline, one from above at an angle of the crown. Then compare which of the stages listed above comes closest to your picture. For the crown, a second mirror or your phone at arm’s length helps.

Keep two questions in mind. First: how far have the hairline and the crown each receded? Second: does the recession come more from the temples and the crown, or does the whole front move back evenly? The second question decides whether your pattern fits the regular series or the type A variants with the „a“. The addition „vertex“, in turn, means that thinning at the crown has joined the receding hairline.

Be lenient with the result. A self-assessment from a photo is rough and varies with lighting, hair length and viewing angle alone. It gives you a direction, no more.

There are two things the scale fundamentally cannot do: it does not say how far your hair loss will progress, and it does not clarify whether hereditary hair loss is behind it at all. A pattern that does not follow the typical picture at the forehead and crown but thins the hair diffusely across the whole head can have other causes. Both questions belong in a medical review. How that works with us is described in the article How the medical review works.

For women, the Ludwig scale applies

The Norwood scale fits the male pattern with a receding hairline and a bald spot at the crown. In women, hereditary hair loss usually follows a different course: the front hairline is generally preserved, while the hair on the part and crown thins across the area. For this pattern, the Ludwig scale with its own grades is used.¹

That is why the Norwood scheme cannot simply be applied to women. What lies behind female hair loss and how it can be classified is dealt with in the article Hair loss in women.

What your stage means for treatment

One thing above all is decisive for treatment: how much of your own hair is still there. The earlier you start, that is, the lower the stage, the more can be preserved. As long as the follicles are still active, treatment can slow the loss and stabilise weakened hair.

In zones that are already completely bald, it looks different. Where no hair has grown for years, the follicles are inactive and have receded, and medication produces no new hair there. For such areas, the comparison between drug therapy and a hair transplant is more relevant, which the article Hair transplant or medication sets out.

So the stage is a reference point, but not a treatment instruction. What makes sense for you and is medically suitable depends on the overall picture: the pattern, the course, your age and your health. That is determined by a medical review, not by the scale alone.

Here is how it works with us: first you answer a medical questionnaire about your hair loss and your health. Our doctors review your answers and decide whether treatment is an option and, if so, which. A prescription is never guaranteed, and the starting point is the medical assessment, not the medication.