- Assoc w/hypokalemia, hyperthyroidism, male, Asian, ages 20-40
- Often precipitated by high carb meals, exercise, stress
- Also a rare familial form (not assoc w/hyperthyroidism), w/male predominance, onset < 20
- Episodic profound weakness
- Muscles affected often proximal
- Duration minutes to hours/days
- Intervals between attacks can be days to weeks to months
- Consciousness preserved during episodes
- No weakness between episodes
- Weakness that's proximal > distal during episodes
- May have findings of hyperthyroidism (tachycardia, tremor, etc)