Medically reviewed by Angela Sheddan, DNP, FNP-BC
Written by Our Editorial Team
Last updated 6/2/2021
Few phrases are the source of as much stress and anxiety in men as these three words: male pattern baldness.
Hair loss is an extremely common issue for men. In fact, research has found that 16 percent of men aged 18 to 29 and 53 percent of men in their 40s already have moderate to extensive hair loss.
While male pattern baldness can be alarming and stressful, it’s not something that happens all at once.
Instead of suddenly waking up without any hair, most guys go bald gradually over the course of years and decades.
Unfortunately, many men fail to notice their hair loss -- and more importantly, to take action and treat it -- until it’s too late.
Because male pattern baldness happens gradually, it’s possible to track the stages of hair loss using a system called the Norwood scale.
Below, we’ve explained how the scale works and listed the seven stages you may go through if you’re losing your hair.
We’ve also discussed your options for treating male pattern baldness, protecting your hair and, in some cases, regrowing hair in areas of your scalp that already have noticeable thinning.
As we mentioned above, male pattern baldness isn’t something that occurs overnight.
Instead, it’s a gradual process that can start with a small amount of hair loss and become more severe over the course of years and decades.
Before we get into the specific stages of male pattern baldness, it’s important to quickly go over the basics of how and why male pattern baldness happens in the first place.
Male pattern baldness is caused by a combination of your genes and the effects of a hormone called dihydrotestosterone, or DHT.
Your body produces DHT as a byproduct of testosterone. Over time, DHT can bind to receptors in your scalp and cause your hair follicles to miniaturize, or shrink, preventing the growth of new hair.
This process usually starts at your hairline before affecting the rest of your scalp, resulting in the classic M-shaped receding hairline and/or bald patch around the crown of your head.
Because hair loss tends to occur slowly, it’s often difficult to keep track of any changes that take place in your hairline or scalp over time.
Fortunately, there’s a simple system that you can use to keep track of your hair loss so that you don’t wake up one day only to find that half your hair has fallen out.
It’s called the Hamilton-Norwood classification system, or Norwood scale.
Originally developed in the 1950s by James Hamilton, it was revised by dermatologist Dr. O’Tar Norwood in 1975 to categorize hair loss into seven distinct stages.
The Norwood scale covers all of the major stages of hair loss, from a hairline that’s completely unaffected by male pattern baldness to total hair loss that affects the entire scalp.
If you’re worried about hair loss, you can use the Norwood scale to determine how severe your hair loss is.
The further you are down the scale, the more your male pattern baldness has likely progressed.
The earlier you can catch your male pattern baldness, the more successful you’ll typically be at treating it and preventing it from getting worse.
We’ve described each stage of the Norwood scale below, along with actionable information on what you can do to treat your hair loss as it progresses from one stage to the next.
The first stage of the Norwood scale, or Norwood Type 1 hair loss, is a full head of hair with little to no recession of the hairline and no hair loss around the crown.
It’s normal to have this type of hairline during your teens and 20s, before male pattern baldness starts to kick in.
If you have a Norwood Type 1 hairline, consider yourself lucky.
This type of hairline is very rare in men as they get older, although it’s not so uncommon to maintain this kind of hairline in your 20s and 30s if you’re not genetically predisposed to male pattern baldness.
There’s no need to treat stage one hair loss, although it’s still worth taking note of your hairline to spot any changes as they occur.
Men with triangular recession around their frontotemporal hairline (the area around the temples) are described as having Norwood Type 2 hair loss, or stage two hair loss.
This type of hair loss is fairly mild, but still visible. You may be able to see that your hairline has receded near your temples and sideburns, giving your hairline a backwards-sloping angle when it’s viewed from the side.
Viewed from above, your hairline might have a noticeable V or M shape, with the skin visible at your temples.
Norwood Type 2 hair loss is relatively mild. However, if you’re worried about losing your hair, it’s best to take action and start treating hair loss during this stage.
Finasteride works by reducing DHT levels in your body, while minoxidil works by stimulating the growth of your hair.
You can learn more about how these medications work in our guide to what you should take for hair loss.
Norwood Type 3 hair loss is much more visible. During this stage, the hairline recedes more and takes on a clear M or V shape.
Men with Norwood Type 3 hair loss have little or no hair around the temples and a clear receding hairline that’s visible from the front and sides.
While Type 2 hair loss is usually easy to conceal with the right haircut, Norwood Type 3 hair loss is much more difficult to hide.
Some men with this type of hair loss also have thinning around the crown (the area at the top of the head). This hair loss pattern is usually referred to as Norwood Type 3 Vertex hair loss.
If you have Norwood Type 3 hair loss, it’s important to take action to treat your hair loss as soon as possible.
If your hair loss is relatively recent, you may be able to regrow some of the hair that’s fallen out from your crown or around your hairline.
Because you still have a lot of hair left at this stage, a treatment such as hair transplant surgery may be effective for restoring your hairline.
Norwood Type 4 hair loss is more severe and obvious. Men with hair loss in this stage have lots of hair loss around the hairline, giving it an obvious bald appearance.
They have sparse hair or no hair on the vertex scalp, or crown.
Many men with stage four hair loss have a thick band of moderately dense hair that separates their hairline from the balding area around their crown.
If you already have Norwood Type 4 hair loss, it’s important to take action urgently if you’d like to slow down or stop your male pattern baldness.
This type of hair loss is relatively advanced, meaning it’s unlikely that you’ll be able to regrow a large amount of hair.
However, medications like finasteride and minoxidil may help you to keep the hair you still have and potentially improve thickness and coverage.
At this stage, hair transplant surgery can still help to restore thickness and volume to your scalp and hairline.
As hair loss progresses to Norwood Type 5, the band of hair separating your hairline and crown becomes smaller and thinner.
By this stage, you’ll display significant, obvious hair loss around your hairline and crown.
Some men develop Norwood Type 5a hair loss, with more significant hair loss on the scalp and less of a separating band between the hairline and crown.
Hair loss becomes harder to treat as it becomes more severe. If you have Norwood Type 5 hair loss, your treatment options are much more limited than they are if you have milder Type 3 or 4 hair loss.
Medications like minoxidil and finasteride may help to prevent your hair loss from getting worse over time.
However, it’s important not to expect miracles from medication when your hair loss is relatively severe.
At this stage, hair transplant surgery might be a viable option if you’d like to add some coverage to your scalp and hairline.
However, it’s important to have realistic expectations, as you may not have sufficient donor hair to achieve complete coverage.
Norwood Type 6 hair loss is very severe. By this stage, you’ll have lost almost all of the hair that previously made up your hairline and vertex scalp, or crown.
There may still be a band of hair to separate these areas, but it will be sparse and thin.
Although you may still have some hair across your scalp, coverage is minimal and your scalp is clearly visible through your hair in all lighting conditions.
By this stage, the classic horseshoe pattern of hair on the back and sides of your head is easy to see.
By this point, it’s very difficult to treat your hair loss effectively using medication.
While hair loss medications like finasteride and minoxidil might help to prevent further hair loss, you’ve already lost so much that it’s unlikely they’ll have a significant aesthetic impact on your hair.
While you may be able to restore some coverage with a hair transplant, it’s unlikely that surgery can fully restore your hair. You may need to undergo several procedures to achieve a satisfying result.
Norwood Type 7 hair loss is the most severe form of hair loss. By this stage, almost none of the hair on your scalp will be left, aside from a few stray hairs or small areas with relatively mild hair growth.
By this point, the classic horseshoe pattern of hair around the back and sides of your head is all that’s left. This hair may be relatively fine and lacking in density.
Unfortunately, by the time you make it to this stage, your options are very limited.
Because your hair loss is already severe, medications like finasteride and minoxidil aren’t very likely to have a significant impact on your hair’s thickness or appearance.
While a hair transplant may help to give you some coverage, it’s unlikely that you’ll have enough donor hairs for an appealing result.
However, there’s still one option: shave your head and own the fact that you’re bald.
Not only does Mr Clean look unapologetically masculine -- it’s also a simple way to save money that you’d otherwise spend on haircuts.
If you want to protect your hair from the effects of male pattern baldness, it’s important to begin treatment action as soon as you notice the early signs of balding.
Currently, the most effective way to prevent male pattern baldness from worsening and protect your hair is with FDA-approved hair loss medication such as finasteride and minoxidil.
When it comes to hair loss, the earlier you start to take action, the more likely it is that you’ll be able to prevent hair loss and potentially regrow hair.
Insider tips, early access and more.