Chemotherapy uses anti-cancer drugs, which travel around the body and reach the cancer cells wherever they are.
Damage to healthy cells also occurs during this process, especially to cells that are always growing and dividing like the ones that make your hair grow.
Not all chemotherapy causes hair loss but your oncology team can advise you on your own personal situation. Hair should grow back once your treatment is finished. Re-growth may take several months and it may grow back in a different texture for a while but normally regulates itself within a year.