Short for hypothyroidism, hypothyroidism is usually treated with levothyroxine. The goal of hypothyroidism treatment is to restore serum thyroid-stimulating hormone and thyroid hormone levels to within the normal range and requires lifelong medication. The dose of treatment depends on the patient’s condition, age, weight and individual differences. Symptoms of hyperthyroidism such as arrhythmia, tachycardia, palpitations, angina pectoris, headache, fever, vomiting, and menstrual disorders may occur with the use of levothyroxine in excess of the individual’s tolerated dose or with overdose, especially due to the rapid increase of the dose at the beginning of treatment. Patients with hypothyroidism are advised to go to the hospital in time, improve the examination to clarify the cause of the disease, and then carry out treatment under the guidance of the doctor, and follow the doctor’s instructions to use the medication.