Taking propylthiouracil may cause headache, dizziness, arthralgia, swollen lymph nodes, and allergic reactions such as rash and drug rash. Propylthiouracil is an antithyroid drug, clinically it is mainly used for various types of hyperthyroidism, especially for patients with mild condition and mild to moderate enlargement of the thyroid gland; adolescents and children, elderly patients; people with recurrence after thyroid surgery and unsuitable for radiological 131I treatment, it can also be used as an adjuvant treatment for 131I radiotherapy. Some patients may experience headache, dizziness, arthralgia, lymph node enlargement and gastrointestinal reactions such as abdominal distension, abdominal pain, nausea, etc., as well as allergic reactions such as skin rash, drug rash and, in severe cases, granulocyte deficiency when treated with propylthiouracil. During the medication period, the dosage should be taken in strict compliance with the doctor’s instructions, and the dose of the drug should not be increased without authorization to avoid serious adverse reactions. At the same time, regular blood tests should be conducted, and once abnormalities occur, the drug should be discontinued or adjusted according to the doctor’s instructions. In addition, patients with severe hepatic impairment, severe deficiency of white blood cells, and allergy to thiourea drugs should be prohibited from using the drug to avoid increasing the risk of drug use. Propylthiouracil is a prescription drug, before using the drug should be ruled out by the doctor contraindications to the use of the drug, and follow the doctor’s instructions to use, to avoid serious adverse reactions.