Why does chemotherapy cause hair loss?

Chemotherapy causes hair loss because it works by attacking cells that divide fast. Chemotherapy can't tell good cells from bad cells, so it can end up fighting healthy cells that also divide quickly. This includes cells in the mouth, making it sore, and hair cells, making hair fall out.

During chemotherapy, doctors administer poisonous drugs into rapidly reproducing cancer cells. Cancer cells can be the most rapidly reproducing cells in the body. Other cells, including those that contribute to the formation of hair and fingernails, also reproduce quickly. Therefore, while chemotherapy drugs preferentially destroy cancer cells, the same drugs also can destroy the cells responsible for normal hair growth and nail growth. That's why cancer patients sometimes shed hair and nails during treatment. There are no hair-growth stimulants, shampoos, conditioners or cosmetic treatments that can prevent or retard this hair loss. The good news is that once chemotherapy is finished, the hair usually grows back within six months or a year.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.