Chemotherapy is the use of medicine to destroy cancer cells.
Chemotherapy medicines are often put into a vein (I.V.) or taken by mouth as pills or a liquid (oral). This sends the medicine to cells throughout the body. Chemotherapy may also be delivered in several other ways. For example, it may be injected into a muscle or put in a cream that is rubbed on the skin.
Chemotherapy kills fast-growing cells. This includes cancer cells but also some normal cells. This can cause side effects, such as nausea and vomiting. Some side effects go away after treatment is finished. Other side effects may be lasting.