Your choice of hair styles may be killing your hair. You need to learn to vary your styles ever so slightly so that you do not fatigue areas of focus. An area of focus is the area from which your style starts, such as a parting which could be bang in the center of the head or to the side of the head [whether left or right!] or a fringe which could be frontal or sideways.
What this means is that if you like to wear a center parting all the time for instance, you will have to learn to shift the parting slightly sometimes from left to right, but just slightly off the center. This helps to vary your look and puts less pressure on the parting being on the same spot for many years.
If you do not, you will soon find that even when your hair is not combed or brushed, a space always appears just where your parting has/had always been. People who have worn a parting on the same spot for a number of years will find they suffer from this syndrome. It can be very difficult to train the hair away from a parting that has become a staple.
But it can be done; the challenge is for the client to be open-minded enough to want to change the location of her parting.
When hair starts to thin out from around your preferred parting spot, it is time to change the location and give the hair in that area a chance to recuperate.