Chemotherapy (also called chemo) is a type of cancer treatment that uses drugs to destroy cancer cells.
Chemotherapy works by stopping or slowing the growth of cancer cells, which grow and divide quickly. But it can also harm healthy cells that divide quickly, such as those that line your mouth and intestines or cause your hair to grow. Damage to healthy cells may cause side effects. Often, side effects get better or go away after chemotherapy is over.
You may get treatment in cycles. A cycle is a period of chemotherapy treatment periods followed by a rest period. For instance, you might receive one week of chemotherapy followed by three weeks of rest. These four weeks make up one cycle. The rest period gives your body a chance to build new healthy cells.