High blood pressure after taking thyroid medication may be caused by thyroid hormones taken for hypothyroidism. Thyroid hormone can promote normal growth and development, metabolism and thermogenesis. Usually, after the development of hypothyroidism, it is necessary to follow the doctor’s prescription to take thyroid hormone treatment, the common drugs are mainly levothyroxine sodium. Failure to take the relevant dose prescribed by the doctor may result in nervousness, irritability, increased heart rate, increased cardiac output, and increased blood pressure. When blood pressure rises after taking the medication, regular monitoring of blood pressure is required. If hypertension persists for a long period of time, it is recommended to stop taking the medication and consult a doctor in time to avoid delaying the condition.