Chemotherapy Complications

Overview

Chemotherapy uses powerful medicines to kill or slow the growth of cancer cells, which divide rapidly. Because some healthy cells in the body also divide quickly, chemotherapy can affect them too, leading to side effects and complications. The cells most often affected line the digestive tract, the hair follicles, and the bone marrow, where blood cells are made.

Most side effects are temporary and improve after treatment ends, but some can be serious or long-lasting. The type and severity depend on the specific drugs, the doses, the schedule, and the individual person. Modern supportive care has made many complications more manageable, and care teams watch closely for problems so they can be treated early.

Common Side Effects

Side effects vary by drug, but several are common across many chemotherapy regimens.

• Low blood counts: Fewer white cells (raising infection risk), red cells (causing anemia and fatigue), and platelets (causing easy bleeding or bruising).
• Nausea and vomiting: Often well controlled with anti-sickness medicines.
• Fatigue: A deep tiredness that is one of the most common effects.
• Hair loss: Temporary thinning or loss of hair.
• Mouth sores and taste changes: Soreness, ulcers, or a metallic taste.
• Diarrhea or constipation and reduced appetite.

Serious Complications

Some complications require prompt or emergency medical attention.

• Neutropenic fever: A fever when white blood cell counts are very low. This is a medical emergency because infection can spread quickly without enough infection-fighting cells.
• Severe infection or sepsis: Can develop rapidly during low counts.
• Nerve damage (neuropathy): Numbness, tingling, or pain in the hands and feet from certain drugs.
• Heart, kidney, or lung effects: Some agents can affect these organs and need monitoring.
• Blood clots and bleeding: Cancer and some treatments increase clotting risk, while low platelets increase bleeding risk.
• Tumor lysis syndrome: A rapid breakdown of cancer cells that disturbs body chemistry, mainly early in treatment of certain cancers.

Risk Factors

• High-dose or combination chemotherapy regimens
• Older age or being in poorer general health
• Existing heart, kidney, or liver conditions
• A large amount of cancer in the body before treatment
• Other medications that affect blood counts or organ function

Monitoring and Diagnosis

Care teams monitor for complications throughout treatment and investigate any new symptoms.

• Blood tests: Regular full blood counts track white cells, red cells, and platelets; other tests check kidney, liver, and electrolyte levels.
• Symptom checks: Reviewing nausea, neuropathy, mouth soreness, and energy levels at each visit.
• Targeted tests: Heart scans, lung tests, or imaging when a specific organ effect is suspected.

People are usually given clear instructions on which symptoms, especially fever, to report immediately.

Management and Prevention

Many complications can be prevented or treated with supportive care alongside the cancer treatment.

• Anti-sickness medicines: Given before and after chemotherapy to control nausea.
• Growth factor injections: Can help the bone marrow recover white cells and lower infection risk in selected people.
• Prompt antibiotics: Started urgently for fever during low counts, often before the exact infection is identified.
• Transfusions: Red cells or platelets when counts fall too low.
• Dose adjustment: Changing the dose or schedule if side effects are severe.
• Practical care: Mouth care for sores, hydration, and good hand hygiene to reduce infection.

When to See a Doctor

People receiving chemotherapy should contact their care team urgently and seek emergency care for any of the following, which can signal a serious complication:

• A fever or feeling shivery and unwell (a possible sign of infection with low white cells)
• Uncontrolled bleeding, many new bruises, or blood in vomit or stool
• Severe shortness of breath, chest pain, or a fast heartbeat
• Severe or persistent vomiting or diarrhea with signs of dehydration
• New leg swelling or pain, which may indicate a clot

Always follow the specific instructions your cancer team gives, as the threshold for calling is intentionally low.

Related Topics

Frequently Asked Questions

References

1. National Cancer Institute (NCI). Chemotherapy side effects.
2. American Cancer Society. Managing chemotherapy side effects.
3. MedlinePlus, U.S. National Library of Medicine. Chemotherapy.