Headache and diarrhoea for three days: what to know

Diarrhoea removes water and electrolytes from the body, and that loss can cause headache, thirst, weakness, dizziness, or a dry mouth. A stomach infection, food-related illness, medicine effect, or another bowel problem may be responsible. The headache does not by itself identify the cause of the diarrhoea.

Track stool frequency and appearance, vomiting, abdominal pain, temperature, urine amount and colour, recent meals, travel, sick contacts, and antibiotic use. These details help a clinician judge infection and dehydration risk.

Take frequent small sips of water and an oral rehydration solution prepared as directed. Continue light foods when able, such as rice, soup, bread, or bananas, and avoid alcohol. Wash hands carefully and avoid preparing food for others while unwell. Ask a pharmacist before using anti-diarrhoeal medicine, especially if you have fever, blood in stool, or severe pain.

Seek urgent help for confusion, fainting, severe weakness, very little urine, inability to drink, blood or black stool, severe abdominal pain, or a sudden severe headache. Contact a clinician now if diarrhoea has continued for three days, or sooner for a young child, older adult, pregnancy, or a long-term medical condition.

Ask whether you need examination or stool testing, which rehydration product is suitable, and which medicines to pause or avoid. Mention travel, food exposures, antibiotics, and your urine output.