Chemotherapy is a medicine that destroys cancer cells. Chemotherapy works by shutting down cell growth. But since all cells in the body grow, chemotherapy medicines also destroy some normal cells and cause side effects. Not all drugs that treat cancer are considered chemotherapy, for example, immunotherapy is different.
Sometimes after you have gotten a chemotherapy drug for a while, the cancer cells become resistant to it. The chemotherapy stops killing them. If this happens, your doctor may try a different drug.
Chemotherapy has a reputation for unpleasant and sometimes dangerous side effects. New chemotherapy drugs are often less bothersome than older ones. And doctors now have better treatments for some side effects.
The most common side effects are:
Chemotherapy often affects healthy blood-forming cells in the bone marrow. This can lower your number of blood cells, which can cause:
Low blood count (anemia), if your red blood cell count is lowered
Serious infections, if your white cell count is lowered
Bleeding, if your platelet count is lowered
Anemia can cause:
Infections from low white cell count can cause:
Low platelet count can cause:
Chemotherapy can also affect other organs besides your bone marrow and cause other medical problems:
Damage to your lungs, heart, or liver
Infertility (trouble getting pregnant)
Sometimes a higher chance of getting another cancer such as leukemia