How male pattern baldness usually progresses (long)
hi jfrank,
just as tynan and krooksbane have said, its different for every person. But USUALLY the hairline above the temples recedes first, before any other change is noticeable. Once the hairline has receded past the normal mature NW2 position, there may be some generalized thinning all over the front. And yes, the middle of the hairline usually lags behind the sides (temples) i.e. it starts receding only after the sides are already NW2. (BTW, it is written on some sites that NW2 includes mild MIDFRONTAL recession as well as some temple recession - in my experience that's very rare, mature hairline is usually only temple recession. If you ask a non-balding man over 30 about how his hairline has changed since his teenage days, he will most likely tell you that its only the temples which have receded some - the middle hairline is still sitting exactly where it was in adolescence)
Crown thinning usually starts once the person reaches NW3 or so, and there is already deep temple recession and significant frontal thinning. The top will also have thinned simultaneously, though the crown nearly always has worse thinning than the top. Also, there is a segment of the top just above the crown, which will be quite thick compared to the rest of the top, front and crown. This is the "bridge" which separates the bald crown from the receding hairline in NW4 and NW5. This breaks down much later than the rest of the hair on the top. In NW6, most of the bridge has gone, and the top is now bald - but the sides of the bridge are still there, which look like a triangular segment of hair when seen from the side. In NW7, the sides of the bridge have disappeared, the bald crown is very expansive, extending quite far down the back of the head, and the hair on the nape of the neck is also mostly gone. Most NW7s have also lost their temple hair (that little triangular projection of hair which juts out from the hair on the sides of the head to join the hairline) NW7 is a severe form of male pattern baldness, a lot worse than NW6, even though they are only one class apart. Most people who reach NW7 begin losing hair very early in life and at quite a fast rate - generally (though not always) people who begin thinning at an average or later than average age and at a normal rate don't go further than NW6.
So to sum up, the most common sequence of thinning is:-
1. Receding hairline above the temples only.
2. Generalized frontal thinning, with or without recession of the middle portion of the hairline (in some people, the middle is remarkably stable, persisting even when the rest of the top is already a NW5 or NW6.)
3. Crown thinning (accompanied by some thinning of the top)
4. Further receding of the temples and front, and crown thinning progressing to form a bald spot on the crown.
5. Both the receding hairline and bald crown keep increasing in size, until the bridge breaks down, and the top of the head is bald, with only the horseshoe band of hair remaining.
Possible signs of future severe baldness (NW7) are:-
1. Significant thinning or receding of the temple hair.
2. Thinning on the nape of the neck.
Aside from the regular Norwood patterns, there is also the type A (front-to-back) pattern, in which the middle hairline and temples recede together , gradually progressing to the top of the head, with little or no loss at the crown. This is relatively rare.
And finally, there is diffuse thinning, in which the hairline stays put at a NW2 or so, but the entire front , top , and crown thins out simultaneously without involving the DHT-resistant areas (the sides and back). An advanced stage of diffuse thinning would look like a typical NW6 or NW7, except that this stage has been reached directly from a NW2, without passing through Norwood 3-5.
Cheers,
Arjun
