What is the Norwood Scale?

Medically approved by
Dr Earim Chaudry
Last updated
14th July 2021

In 30 Seconds

What is the Norwood Scale? Often also known as the Hamilton-Norwood Scale, it’s the best-known system used to classify male pattern baldness.

Most balding men experience hair loss in a certain pattern — and it’s this pattern that the Norwood Scale shows. The scale has 7 stages. At stage 1, you have no significant hair loss or a full head of hair. At stage 7, you’ll have only a single strip of hair around the back of the head, which itself would be thinning.

Men experience hair loss in different ways. And while the scale is useful, you may not fit exactly into any particular stage. But, whatever your hair loss looks like, it doesn’t have to progress further. Treatments such as Finasteride and Minoxidil can stop male hair loss in its tracks.

Managing Progressive Hair Loss

Many men experience hair loss throughout their lives. In fact, the vast majority of us do. According to the American Hair Loss Association, as many as 85% of us will have signs of significant hair loss by the time we’re 50.

Just how far our receding hairline has progressed, however, will differ from one man to the next. And, of course, it will affect each of us differently too. While some embrace the bald look, others can struggle to adjust.

So, to understand the progression and effects of hair loss, here we take a look at the Norwood Scale — the system by which some scientists have tried to make sense of the pattern of male pattern baldness. This 7-stage progression is something most of us do have in common when it comes to losing our hair.

What is the Norwood Scale?

The Norwood Scale (sometimes known as the Hamilton-Norwood Scale) is a system used to classify the progression of male pattern baldness.

It was introduced back in 1951 by a scientist named James Hamilton, who identified 8 different stages of balding. However, his analysis was corrected by Dr O’Tar Norwood in the 1970s. Norwood’s adapted scale soon became the most famous method to categorise hair loss in men, however, it was only one of many attempts to do so.

Norwood’s scale identified 7 main stages in the progression of hair loss, from a full head of hair to a single band of hair around the back and sides of the head.

The 7 Stages of the Norwood Scale

Norwood’s classification system has 7 stages, which are still used today to understand the progression of male baldness:

  • Stage 1: No significant hair loss and retained hairline.
  • Stage 2: Slight recession of the hairline around the temples. It’s usually symmetrical.
  • Stage 3: The first stage Norwood defines as balding. The temples are only sparsely covered by hair and your hairline starts to resemble an M, U, or V.
    • Stage 3 Vertex: An alternative stage occurs when hair recedes at the crown, or ‘vertex’, without affecting the hairline any further.
  • Stage 4: More severe receding of the hairline and, in the balding area around the crown, there is only very sparse hair. At this stage, there is a patch of hair separating two bald areas.
  • Stage 5: Your hairline has receded further and the balding area at the crown has widened. Only a very thin line separates the hairline from the crown.
  • Stage 6: The balding area stretches across the whole of the top of the head, with only very sparse hairs in the middle.
  • Stage 7: The last of the stages of hair loss leaves you with only a thin strip of hair around the back and sides of the head – usually described as a ‘horseshoe’.

Why Does the Norwood Scale Matter?

The Norwood Scale is most famous as a scientific attempt to make sense of the pattern of hair loss. 

For others, it can help to understand how far your male pattern baldness has progressed — and what you can expect next. That can be important because knowledge can help you feel more in control of your situation. 

However, there’s something worth remembering. Not everyone will fit neatly into the different stages. So, if the scale doesn’t make sense to you, don’t panic. Men experience baldness differently. And some more recent academic studies have found that the Norwood Scale is not always 100% accurate in practice.

Why Does Hair Loss Happen?

The Norwood Scale is a simple way to represent what is happening in your body. But to truly understand why male pattern baldness happens, we need to talk about two things: your hair follicles and your hormones.

Male hair loss happens due to a hormone known as dihydrotestosterone, or DHT. Produced from testosterone, this hormone does lots of great things for your physical development, such as helping to develop your male genitals, your physique, and things like your deep voice and body hair.

However, over time, DHT accumulates in your system. The problem is that your hair follicles — the capsules in your skin that produce hair — are usually sensitive to the hormone. And guess which ones are most sensitive? Those on your hairline, particularly at the temples, and those at the crown. In other words, the places where the Norwood Scale shows you lose hair first.

Thanks to their sensitivity to this hormone, your follicles will slowly shrink, weaken, and stop producing hair. And that means slowly progressing baldness across your scalp until you’re left with only the hardiest follicles — those around the back and sides.

Male Pattern Baldness Treatment Options

The good news is, you’re not always doomed to pass to the later stages of balding that the Norwood Scale shows. You have the power to stop hair loss in its tracks — and, in some cases, to boost hair growth once more.

How? There are two effective medical hair loss treatments out there:

  • Finasteride is a hair loss treatment that works by tackling that aforementioned root cause of hair loss: DHT. The medicine, taken daily as a pill, inhibits the production of this hormone, meaning there is less in your system to damage those follicles. And does Finasteride stop hair loss? You bet. Nearly 90% of men who take it report hair regrowth.
  • Minoxidil is the alternative. This one’s a topical solution that you apply directly to the scalp. It works by encouraging blood flow to your scalp, and the improved circulation delivers all the things your hair follicles need to stay healthy. While Minoxidil is usually used on the crown, it is just as effective on a receding hairline too.

Want to boost your chances of battling baldness? Use both Finasteride and Minoxidil together. Studies have shown that men who use a combined treatment have a 95% chance of hair regrowth.

Important note. When it comes to tackling male pattern baldness, the sooner you start, the better. Treatments work best when your hair follicles are still able to produce hair. The further along the Norwood Scale you sit, the less true that will be.

Key Takeaways

So, what’s the Norwood Scale? A system by which to classify the different stages of baldness, it can be an important tool for understanding how far your hair loss has progressed.

To stop your hair loss from progressing any further, use Finasteride or Minoxidil, or both together. The sooner you start treatment, the more effective it will be. 

References

  1. American Hair Loss Association. Men’s Hair Loss: https://www.americanhairloss.org/men hair loss/introduction.html

  2. Mrinal Gupta and Venkataram Mysore (2016). Classifications of Patterned Hair Loss: A Review: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4812885/

  3. M Guarrera, P Cardo, P Arrigo, and A Rebora (2009). Reliability of Hamilton-Norwood Classification: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2938573/

  4. Akio SatoAkira Takeda (2011). Evaluation of efficacy and safety of finasteride 1 mg in 3177 Japanese men with androgenetic alopecia: https://pubmed.ncbi.nlm.nih.gov/21980923/

  5. Ruiming HuFeng XuYouyu ShengSisi QiYumei HanYing MiaoWenlong RuiQinping Yang (2015). Combined treatment with oral finasteride and topical minoxidil in male androgenetic alopecia: a randomized and comparative study in Chinese patients: https://onlinelibrary.wiley.com/doi/abs/10.1111/dth.12246

While we've ensured that everything you read on the Health Centre is medically reviewed and approved, information presented here is not intended to be a substitute for professional medical advice, diagnosis, or treatment. It should never be relied upon for specific medical advice. If you have any questions or concerns, please talk to your doctor.

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