Hyperthyroidism may lead to low blood potassium. Hyperthyroidism is caused by an abnormal increase in the secretion of thyroid hormones. Increased gastrointestinal motility in hyperthyroidism can cause increased stool frequency or diarrhea, resulting in increased excretion of potassium ions from the intestines, which is one of the causes of low blood potassium. In addition, hyperthyroidism hypokalemic periodic paralysis can also cause lower blood potassium. Patients with hyperthyroidism resulting in low blood potassium should closely monitor the blood potassium level, and should be actively treated with potassium supplementation during episodes of hypokalemia, such as oral potassium chloride or intravenous potassium supplementation as prescribed by the doctor. In the process of potassium supplementation, attention should be paid to monitoring the blood potassium level to prevent the blood potassium from being too high, and attention should be paid to preventing the occurrence of malignant cardiac arrhythmia and respiratory muscle paralysis. At the same time, follow the doctor’s instructions to use methimazole and other anti-thyroid drugs to prevent the recurrence of hypokalemia. Hypokalemia in hyperthyroid patients should go to the hospital in time for consultation and timely treatment to prevent the adverse effects of hypokalemia.