Cancer Hair Loss
If you are having chemotherapy, your hair loss may be gradual or dramatic: clumps in your hairbrush, handfuls in the tub drain or on your pillow. Whichever way it happens, it's startling and depressing, and you'll need a lot of support during this time.

Radiation only causes hair loss on the particular part of the body treated. If radiation is used to treat the breast, there is no hair loss on your head. But there might be loss of hair around the nipple, for women who have hair in that location. Radiation to the brain, used to treat metastatic cancer in the brain, usually causes complete hair loss on the head.
Most women will want to find some way to disguise their bareness—and keep warm. Then it's a matter of what you're most comfortable with: a wig, a scarf, a hat, or a baseball cap.