Stomach flu and headache: what to know

Stomach flu usually refers to gastroenteritis, an infection or irritation of the stomach and bowel. Vomiting and diarrhoea can remove water and salts, while fever, poor sleep and eating less can add to headache. A dry mouth, dark urine, dizziness or unusual tiredness can point toward dehydration. Headache is not specific to gastroenteritis, so consider other causes if digestive symptoms are mild or absent.

Take frequent small sips of water or an oral rehydration drink. If nausea makes drinking difficult, try a spoonful at a time and increase slowly. Rest in a quiet room, eat bland foods when you can, and avoid alcohol. Ask a pharmacist which pain reliever is suitable, especially if you are vomiting, have kidney disease, have liver disease, or take other medicines.

Seek urgent care for a sudden severe headache, confusion, fainting, a stiff neck, trouble breathing, weakness on one side, blood in vomit or stool, or inability to keep fluids down. Arrange medical advice if headache continues after the stomach symptoms improve, dehydration signs develop, or fever and abdominal pain are worsening.

Ask whether the headache fits your other symptoms, which rehydration product and pain medicine are appropriate, and what signs should prompt same-day assessment.