Does childhood cancer cause unexplained fever?

Cancer can affect the immune system and may trigger inflammation, allowing fever to appear without an obvious infection. In children, infections remain a frequent explanation, so a fever alone cannot identify its cause. A clinician considers the child's age, temperature pattern, energy, appetite, other symptoms, examination findings, and any recent illness.

The assessment may include a physical examination and selected tests. These help separate infection and inflammation from blood-related or other conditions. Keep a record of when fever begins, how long it lasts, and symptoms such as unusual tiredness, bruising, bone discomfort, or enlarged glands.

Contact the child's doctor when fever has no clear explanation, keeps returning, or comes with changes in behaviour, eating, drinking, or activity. Offer fluids if the child can drink, follow the clinician's advice about fever medicine, and avoid giving medicines intended for another child. Do not delay assessment because the child briefly seems better.

Seek urgent medical help if the child is difficult to wake, has trouble breathing, appears seriously unwell, cannot keep fluids down, has a seizure, develops a stiff neck, or shows signs of dehydration. A very young infant with a fever needs prompt medical advice. Urgency depends on the child's condition and age, not on fever alone.

Ask what causes should be checked, which symptoms should prompt immediate care, whether a fever diary would help, and when the child should be reviewed if the fever continues.