A fever is the body responding to infection, not the illness itself. In a healthy adult, a fever for two or three days with a runny nose and body ache is usually viral and needs rest, fluids and paracetamol — not an antibiotic.
Come the same day if
- Fever lasts more than three days, or returns after settling.
- There is breathlessness or chest pain.
- Severe headache with neck stiffness, or confusion.
- Rash, bleeding from gums or nose, or black stools.
- Not passing urine, or passing very little.
- The person is elderly, pregnant, or has diabetes, cancer or kidney disease.
Fever in children
Any fever in a baby under three months needs to be seen immediately, whatever the temperature. In older children, what matters more than the number on the thermometer is how the child looks between fever spikes: a child who plays and drinks after paracetamol is usually fine; a child who stays limp and refuses fluids should be seen.
Do not take an antibiotic left over from a previous illness. It will not help a viral fever, and a partial course makes future infections harder to treat.
This article is general guidance, not a diagnosis or a prescription. Your own treatment depends on your history and examination — please discuss it with your doctor.