How common is persistent fatigue in immunotherapy side effects?

Immunotherapy activates the immune system to help it recognise cancer cells. Sometimes that immune activity affects healthy tissues as well. Tiredness may occur as part of this response, or it may accompany inflammation in organs such as the thyroid, adrenal glands, lungs, bowel, liver or muscles. Fatigue may also be linked to sleep disruption, pain, infection, low blood counts, dehydration, poor nutrition or another medicine. The pattern of symptoms and targeted blood tests help the team decide what is happening.

Report fatigue early, even if you are still managing daily activities. Keep a brief note of its effect on walking, work, self-care, sleep and appetite, and mention breathlessness, cough, diarrhoea, rash, headache, dizziness or temperature changes. Your treatment team may arrange a review and tests, then advise whether any medicine or treatment schedule needs adjustment. Do not use steroid medicines left over from a previous prescription unless your clinician tells you to.

Call your oncology service promptly for rapidly increasing exhaustion, new shortness of breath, chest pain, severe diarrhoea, repeated vomiting, fainting, confusion, severe headache or a high temperature. Go to emergency care if breathing is difficult, you collapse, or you cannot stay awake. These symptoms may need timely treatment and should not be managed alone at home.

Ask whether your fatigue could be treatment-related, which symptoms may point to an immune-related problem, and which tests are being considered. You can also ask how to contact the team after hours and whether to bring a list of all medicines, vitamins and herbal products.