1. Fatigue and general weakness: Hypothyroidism, Low Vit b12 level, Guillain-Barré Syndrome , Myasthenia gravis
2. Low blood pressure: Orthostatic hypotension, severe anemia, dehydration
3. Cardiac reason: Congest heart failure, cardiac arrhythmia
4. Large vessel stenosis in the neck, not like stroke
5. Side effect of medications: low blood glucose level by using insulin, low blood pressure by using HTN medications et al.
