Hypokalemic thyrotoxic periodic paralysis is a potentially life-threatening complication of hyperthyroidism, defined by 3 characteristic features: thyrotoxicosis, hypokalemia, and acute painless muscle weakness. In this case, a 25-year-old Malaysian man presented with acute, painless lower extremity weakness immediately after a meal. His associated symptoms included palpitations, tremor, and anxiety. He also reported a 30-pound unintentional weight loss over the previous 18 months, dyspnea on exertion, and insomnia.