What should you know about headache, diarrhea, nausea and fatigue?

This combination often occurs when an illness affects the digestive system or when fluid and salts are lost. Viral illness, food-related illness, heat exposure and medication effects are possible explanations. The symptoms do not identify one diagnosis by themselves. COVID-19 or Dengue Fever can also cause headache and tiredness, while diarrhea may make Dehydration develop more quickly.

Take frequent small sips of water or an oral rehydration drink. Continue light foods as tolerated, such as soup, rice or toast, and rest. Wash hands carefully and avoid preparing food for others while diarrhea continues. Do not start antibiotics without medical advice. A pharmacist can advise on symptom medicines, particularly if you are pregnant, have kidney disease, or take regular treatment.

Seek urgent help for confusion, fainting, severe weakness, severe abdominal pain, a stiff neck, trouble breathing, blood or black material in stool, or inability to keep fluids down. Contact a clinician promptly for signs of dehydration such as very little urine, a dry mouth or worsening dizziness, or if symptoms persist or intensify. Fever after travel or a spreading rash warrants assessment for illnesses such as Dengue Fever.

How should I replace lost fluids? Do my medicines or recent food, travel or contact history change the likely causes? Which symptoms mean I should return urgently?