A Top Expert Research Physician On Chronic Fatigue (CFS)
When To Seek Medical Help
⚠ Sudden, severe fatigue that peaks within seconds to minutes
⚠ Fatigue accompanied by chest pain, shortness of breath, or neurological changes
⚠ Onset after trauma, head injury, or toxic exposure
⚠ Progressive worsening over days or weeks without a clear cause
⚠ Fatigue in a high-risk individual (age >65, immunocompromised, or pregnant)
⚠ Sudden onset of severe fatigue — “thunderclap” or “worst-ever” character
What Causes Fatigue? Common and Rare Causes Explained | vHospital (opens in new tab). Assessed July 31, 2026.