It can be triggered by hormonal changes from having gone through perimenopause and menopause and you're living with less estrogen. Estrogen loss causes all sorts of problems.

I went through menopause six years ago and can't do HRT because of a medical condition I have. I had all sorts of hair breakage issues for a while leading up to menopause, during menopause and had to use collagen shampoos and conditioner for a couple of years. I currently use lightweight moisture shampoos and that cuts back on the hair breakage without weighing my hair down and making it look greasy like heavy moisturizing shampoos can do.