Skip to main content

The Science Behind Hair Breakage and Shedding

• Apr 21, 2015

Can you tell the difference between shed hair and broken hair? On the surface, it appears to be an irrationally simple question.

Shed hair will have a visible bulb and tends to be longer (closer to the full length of your hair) while breakage is typically a shorter segment of hair without a visible bulb, just like the images below, right?


Typical breakage — Inset magnified microscopic view of broken hair with damage to strand highlighted in white (full length of broken hair — just over 0.25 inches)


Typical shed hair — Inset magnified microscopic view showing hair bulb with sheath (full length of shed hair — 11 inches)

Well if you thought that was the long and short of it (pun intended), you may well be very wrong. Sometimes breakage can appear as long segments and if you only look for longer lengths to indicate shed hair and not the bulb of hair you may well be underestimating the amount of breakage you are having.

Why does hair break in short segments?

Scientifically, there are quite a few theories and experiments as to why this happens but the two that I find quite credible are

1. Dry combing of hair (e.g during styling) produces short hair segments which increase with increasing number of comb strokes — simply put, the more you comb dry hair, the more damage it sustains, the easier it breaks. (J Cosmet Sci, pp 477–484, 2007)

2. Hair ends that are damaged and intertwined have a tendency to break, producing the typical short broken hair. (J Cosmet Sci, pp 245–257, 2006)

Why does hair break in long segments?

Breakage is not all about short pieces of hair. You can find lengths of an inch and longer as breakage. The experiments in the lab say that this happens because:

1. Wet/Conditioner combing of hair tends to produce longer segment breaks however hair breakage does not increase the longer you conditioner comb. (J Cosmet Sci, pp 477–484, 2007)

2. Longer segments of breakage tend to occur where hair is less resistant to impact e.g at a kink where here is naturally weaker and cannot withstand the same combing force as another part of the hair without a kink. (J Cosmet Sci, pp 245–257, 2006)

Can you stop breakage completely?

No, it is not a practical consideration to say that you will never have breakage. In truth, it is possible if you just never style, wash or touch your hair. Some breakage is going to happen naturally. You can minimize it by selecting the combing method that produces the least amount of breakage for you. For some that will be dry combing, for others it will be conditioner combing and for some it will be something in between.  Additionally, trimming hair before it sustains sufficient damage to break easily is also an option.

The key message is that do not look at all long segments of hair and think that they are just shed hair, sometimes they are not. This is very important in the event you find yourself at a stagnant stage or even going backward with progress in the length of your hair or volume at the ends of your hair.


Based on the info above, do you experience primarily shedding on breakage?

About The Natural Haven

Scientist on a hairy mission!

Notify of
Inline Feedbacks
View all comments
7 years ago

Breakage prevention is probably my number one goal in retaining length. I had big problems in the past because I was aggressively comb detangling and although my hair is growing nicely, it’s still hard to prevent breakage at my front section. I always moisten my hair before combing but have recently been using a comb less in favor of finger detangling. It’s much more gentle and does the job just the same. In addition, detangling under water has been a false comfort for me. I’m now doing some finger detangling for that as well.

7 years ago

I would love to know more about post partum shedding. I have a 10 month old and while I was pregnant with him my twa grew enormously! It’s now shedding like crazy and I was hoping it would have stopped by now but the doctor says it could take up until my son’s 1st birthday before it fully recovers. I want to know is it shedding until it goes back to the original twa? Because I am so confused and stressed watching it all fall out 🙁

Would love your thoughts, please comment.x

Shopping Cart