The condition is hyperthyroidism cycle paralysis, clinically more men than women. Most of them have no obvious pre-symptoms, often with triggers: satiety, fatigue, mental stress, high sugar diet, cold and other circumstances of the attack, the attack of both lower limbs or quadriplegia, severe cases can lead to respiratory muscle paralysis. On physical examination the patient is clear. Laboratory tests for blood potassium are mostly decreased. The possible mechanism is due to the elevated glucose level in hyperthyroid patients with sugar load or after a full meal. With the accelerated process of sugar oxidation, catabolism, and utilization, the extracellular K+ moves rapidly to the intracellular, and the abnormal distribution of serum potassium is caused. In some patients, it occurs after emotional excitement, which is caused by sympathetic excitation, adrenaline, thyroxine massive release, elevated blood glucose, and similarly abnormal distribution of blood potassium. The clinical symptoms of this disease are similar to those of periodic paralysis, and the symptoms can be relieved rapidly after potassium supplementation. The fundamental treatment for this disease is to treat hyperthyroidism. When hyperthyroidism is effectively controlled, periodic paralysis usually does not recur, but when hyperthyroidism recurs, periodic paralysis will follow, therefore, 131I treatment is a better choice for treatment. After hyperthyroidism is cured, the condition will not flare up again, but a few patients still have flare-ups, which may be due to the coexistence of both hyperthyroidism and periodic paralysis.