Why is chemotherapy-related hair loss temporary? Chemotherapy kills cancer cells by targeting rapidly growing cells. That is why patients lose hair as well. Why is chemotherapy-related hair loss temporary? The doctors say it is because healthy cells are able to repair themselves. But, if that is true, then people should not even lose their hair, as the damaged hair cells would repair themselves before patients lost their hair.

Its less that the cells repair themselves and more that the _tissue_ can repair itself. Rapidly dividing tissues have reservoirs of stem cells waiting to replace the cells that are rapidly lost. For instance, histologically, there are stem cells just waiting at the hair follicles and intestinal lining, waiting to replace the old cells that rapidly die off. But those are killed off during chemo.

Stem cells at the follicles:

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