The side effects of chemotherapy depend mainly on the drugs being used; and, as with other therapies, may vary from person to person.

Anticancer drugs generally affect dividing cells. Because cancer cells divide more often than healthy cells, they are more likely to be affected by chemotherapy. However, healthy cells that divide often may also be damaged by chemotherapy. Cells in this category include blood cells, cells in hair roots, and cells in the digestive tract.

When chemotherapy affects healthy cells, side effects may include, lowered resistance to infection, a tendency to bleed more easily, fatigue, nausea, loss of hair, vomiting, and mouth sores. Most side effects disappear gradually during the recovery periods between treatments or after treatment stops. Some anticancer drugs can also affect fertility, and these changes may be permanent. Patients are advised to ask about side effects prior to treatment. (see also: What questions should I ask prior to chemotherapy?)