Hair Shedding and Anemia
If you are suddenly noticing a lot more hair in your hairbrush or on your shower floor, this could be a sign that your body has low iron stores, or anemia, and may warrant testing. "This is another blood test we do when you complain of hair changes," says Mirmirani. She says she is particularly likely to order this blood test for people who are vegetarian or for women who have heavy periods, both of which increase the chance that hair changes are due to low iron. Iron supplements or a change in diet to include more iron-rich foods can help you keep your hair.
Hair shedding can also happen (temporarily) with sudden changes in estrogen levels and is often noticed after pregnancy or stopping birth control pills.