What to Expect During Chemotherapy

How chemotherapy works

Chemotherapy uses medicines that target rapidly dividing cells. Cancer cells divide more often than most healthy cells, which is why chemotherapy can shrink tumors — but the same mechanism is why it also affects fast-growing healthy tissue like the lining of the mouth, the stomach, hair follicles, and bone marrow.

Your oncologist chooses a regimen based on the type and stage of your cancer, your overall health, and the goal of treatment (curative, controlling growth, or relieving symptoms). Many regimens combine two or more drugs given on a fixed schedule called a "cycle."

A typical infusion day

Most chemotherapy is given as an infusion through a vein, often via a port placed under the skin in the upper chest. Some regimens are oral tablets you take at home.

1. Check in and have blood drawn so the team can confirm your counts are safe to treat.
2. Meet briefly with your oncologist or nurse practitioner to review side effects since the last cycle.
3. Receive pre-medications (often anti-nausea drugs and steroids) before the chemotherapy itself.
4. The chemotherapy infusion runs for anywhere from 30 minutes to several hours depending on the regimen.
5. A nurse monitors you throughout and removes the IV (or de-accesses your port) when finished.

Common side effects to watch for

Side effects vary by drug, but most patients experience some combination of fatigue, nausea, taste changes, and lower blood counts. Side effects often peak 7–10 days after an infusion and improve before the next cycle.

• Fatigue that is not relieved by sleep — pace activities and accept help.
• Nausea — anti-nausea medications work best when taken on a schedule, not waited for.
• Mouth sores — rinse with a saltwater-baking-soda mix several times a day.
• Low blood counts — fever ≥ 100.4°F (38°C), unusual bruising, or shortness of breath are reasons to call your team immediately.

Questions to ask your team

What is the goal of this regimen for me — cure, control, or symptom relief?

Knowing the intent shapes how you weigh side effects, schedule decisions, and dose adjustments. Ask your oncologist to state the goal in plain language.

Which side effects should make me call you, and which can wait until my next visit?

Fever, chest pain, severe shortness of breath, persistent vomiting, and signs of infection at the port site warrant a same-day call. Mild fatigue or nausea you have a plan for can usually wait. Ask for an after-hours phone number.

Can I keep working, exercising, or traveling during treatment?

Most patients keep doing what they can — light to moderate exercise actually helps fatigue. Plan demanding events for the second week of each cycle, when counts have usually recovered.