Diarrhea, headache and fatigue

Diarrhea reduces fluid and electrolyte stores, which can leave you tired, light-headed and headachy. An infection may add fever, poor appetite and muscle weakness. COVID-19 can include digestive symptoms and fatigue, while a common cold or sinus condition can cause headache with a separate bowel illness. Heat exhaustion is possible after time in a hot environment, particularly with sweating, dizziness or nausea. Dengue fever should be discussed after mosquito exposure with fever, rash or strong body aches. Anxiety can worsen fatigue and bowel urgency, but new physical symptoms still deserve a basic medical review when they persist.

Use frequent small sips of water or oral rehydration solution, then increase fluids as tolerated. Rest, keep cool and choose gentle foods such as soup, rice or toast. Keep a short record of stools, urine, temperature, sleep, medicines and recent travel. Avoid alcohol and strenuous exercise until strength and hydration improve. Do not take leftover antibiotics; they may be unsuitable and can worsen diarrhea.

Seek urgent help for fainting, confusion, severe weakness, breathing difficulty, a sudden severe headache, stiff neck, blood or black stool, severe pain or repeated vomiting. Contact a clinician promptly if urine is markedly reduced, fatigue is worsening, symptoms continue beyond a short illness, or you have recently travelled or been exposed to heat. People who are pregnant, very young, older or immunocompromised should seek advice earlier.

Could dehydration, infection or a medicine explain all three symptoms? Should I check for fever, electrolyte problems or another illness? What fluids and foods suit my medical history? When can I safely return to work or exercise?