Norwood Scale: Causes, Stages & Treatments

Male pattern hair loss is an extremely common condition. It affects half of all men by the time they’re 50 — with some people beginning to lose hair as early as their late teens or early 20s [1] [2].

But while pattern baldness (also known as androgenetic alopecia) affects most men at some point in their life, the degree of hair loss — and the impact on your life — varies enormously. As a result, many researchers have proposed ways to classify and measure male pattern baldness. The best known classification is called the Norwood scale.

Find out how the Norwood scale describes each stage of male pattern baldness, and how it’s used to measure hair loss and propose potential hair restoration treatments.

What is the Norwood scale?

Although the Norwood scale has been around for some time — it was first proposed in 1975 — it’s still the most popular scale for diagnosing male pattern hair loss worldwide [3]. This is because it’s easy to understand and has a high level of detail.

The Norwood scale (also sometimes known as the Hamilton-Norwood scale, as it builds on the 1951 Hamilton classification chart) was devised following the study of hair loss in 1,000 male patients. It’s now used to define, diagnose, and predict hair loss patterns in men experiencing androgenetic alopecia.

Many hair restoration clinics also use the Norwood Scale to determine the number of grafts required for hair transplant surgery and to provide quotations. We recommend reading our UK analysis if you are interested in understanding hair transplants costs in the UK. You can also find out more about the cost of a crown hair transplant.

The Norwood scale splits male pattern hair loss into 7 distinct stages, which focus mainly on typical hair loss around the temples and crown.

The 7 stages of male pattern hair loss

Each stage of male pattern baldness is characterised by a specific amount of hair loss in a given area. Here’s how the Norwood scale defines each stage of hair loss.

Image showing the 7 stages of male pattern balding according to the Norwood scale. Image credit: Healthline

Stage 1

The first stage refers to a standard adult hairline with little to no balding. There’s also no hair loss around the crown. You may notice a little shedding around the temples, but this doesn’t manifest in visible hair loss at this stage.

Average grafts required: 0

Stage 2

The hairline starts to recede slightly at the temples at Norwood 2, though there’s still no visible thinning around the crown. This is sometimes considered a mature hairline. You may also see slightly more hair thinning on one side of the head than the other. While you may be concerned about this recession, the Norwood scale considers this hairline to be unaffected by male pattern balding.

Average grafts required: 500-1,000

Stage 3/stage 3 vertex

This is the earliest stage that the Norwood scale considers balding. The hairline recedes more dramatically, with a typical M-shaped pattern starting to form at the temples. Alternatively or in addition, you might start to see thinning around your crown (this is known as stage 3 vertex).

See more Norwood 3 stages of hair loss and surgical restoration results.

Average grafts required (temple): 1,000-1,500
Average grafts required (crown): 500-1,000

Stage 4

Norwood stage 4 hair loss consists of more extensive hair loss in the same areas as stage 2 and 3: namely, the temples and the crown. However, there’s still a substantial amount of hair separating the crown from the hairline. If no hair is lost from the crown, hairline recession is much greater than in stage 3.

Average grafts required (temple): 1,200-2,500
Average grafts required (crown): 800-1,100

Stage 5

Hair loss on the crown and temples increases. The hair separating the 2 areas is still there, but becomes thinner as more hair is lost. If no hair is lost from the crown, hairline recession is much greater than at Norwood stage 5 than during stage 4.

Average grafts required (temple): 1,800-2,500
Average grafts required (crown): 1,000-1,500

Stage 6

At Norwood stage 6, the band of hair separating the crown from the receding hairline starts to disappear. Hair loss is substantial around the front and top of the head. If there has been no balding at the crown, the hairline now recedes almost to the back of the head.

Average grafts required (temple): 1,800-2,500
Average grafts required (crown): 1,500-1,700

Stage 7

This is the most advanced stage of hair loss according to the Norwood scale. There is typically just a band of hair around the sides and back of the head. The top of the head is almost completely bald. By this point it may be too late for a hair transplant, though there have been some successful examples of completely bald hair transplants.

Average grafts required (temple): 2,500+
Average grafts required (crown): 1,700+

Find out how many hair grafts you need for your hair transplant procedure.

How do trichologists use the Norwood scale?

When you have a hair loss consultation, a trichologist will examine your hair and scalp to determine the cause and extent of your hair loss. The Norwood scale is a vital tool for diagnosing your hair loss.

At a basic level, a trichologist can use the Norwood scale to determine the current stage of your hair loss. This enables them to recommend treatment for your existing hair loss. If you’re diagnosed with hair loss in the early stages (usually 2 or 3) your trichologist may recommend hair loss drugs like Finasteride or topical solutions like Minoxidil to retain and thicken your hair.

The Norwood scale can also be used to predict how your hair loss will progress through each scalp zone:

Male pattern baldness is largely hereditary, so in conjunction with knowledge of your family history, a trichologist can use the Norwood scale to suggest where your hair loss will stop [4]. This enables you to plan for your potential future hair loss. You can reduce current shedding, stimulate growth, and prepare for a future hair transplant if necessary.

Trichologists can only use the Norwood scale to make diagnoses and predictions based on male pattern baldness. It can’t be used for female pattern baldness (the Ludwig scale is often used for this) or temporary hair loss like telogen effluvium [3].

Norwood Scale FAQs

Do all men with hair loss reach Norwood stage 7?

No — the ultimate extent of your hair loss largely depends on your genetic predisposition to male pattern baldness, as well as the levels of dihydrotestosterone (DHT) in your body. So even if you progress to a stage 4 or 5, you may never progress to Norwood stage 7. If you’re worried about the progression of your hair loss, talk to a trichologist.

Can a hair transplant be performed at any stage of the Norwood scale?

No. Some people — typically those with Norwood stage 1 or stage 2 hair loss — don’t have enough hair loss to be eligible for a hair transplant. Instead, non-surgical methods are used to preserve hair and stimulate growth.

On the other hand, it may be too late for a hair transplant if your hair loss has progressed to stage 6 or 7. If you don’t have enough healthy donor hair to fill in your balding areas, a hair transplant may be unsuccessful. That’s why it’s important to get advice from a reputable clinic early, so you can manage your hair loss and preserve your donor follicles.

Can you stop your hair loss advancing to further stages of the Norwood scale?

Yes! While no treatment is guaranteed to be 100% effective, there are many non-surgical hair restoration methods available which offer excellent results. These are often recommended if it’s too early for you to get a hair transplant.

One study found that Finasteride prevented further hair loss in 83% of participants with male pattern baldness [5]. In a separate study, 62% of patients reported that the areas affected by hair loss had grown smaller thanks to the use of Minoxidil, while 35% said they had lost no additional hair [6].

What are the limitations of the Norwood scale?

While the Norwood scale is a very popular way to diagnose male pattern hair loss, some researchers suggest it can only be used to classify patients in a very broad way that’s unhelpful for modern surgeons [3] [7]. With technological advances in computer-assisted hair density measurements, there may soon be a more accurate way to define and predict hair loss patterns in men [7].

At which Norwood stage should you seek hair loss treatment?

No matter which Norwood stage you’re at, if you’re worried about your hair loss, you should seek help from a professional trichologist. In many cases, the earlier your hair loss is addressed, the better — tackling the problem early can minimise or even prevent the need for a hair transplant.

If your hair loss is advanced, you may still be eligible for a hair transplant. Get a free hair loss examination at the Wimpole Clinic to find out if a hair transplant is right for you.

Sources:

1. Male pattern baldness: classification and incidence
2. An Overview of Alopecias
3. Classifications of Patterned Hair Loss: A Review
4. Understanding Pattern Hair Loss-Hair Biology Impacted by Genes, Androgens, Prostaglandins and Epigenetic Factors
5. Finasteride: a review of its use in male pattern hair loss
6. Effectiveness Of 5% Minoxidil In Treating Male-Pattern Hair Loss
7. Reliability of Hamilton-Norwood Classification