Radiation thyroiditis may occur after iodine 131 treatment, causing a transient elevation of thyroid hormones, which can lead to increased heart rate. Hyperthyroidism after drinking iodine 131 heart rate increase, according to the situation in the treatment with iodine 131 after the administration of anti-thyroid drugs, may also be iodine 131 has not yet taken effect related, should continue to observe. 1. After drinking iodine 131 for hyperthyroidism, there may be a transient increase in thyroid hormones. At this time, you can choose to continue to give anti-thyroid drugs such as methimazole and propranolol after iodine 131 to carry on the treatment, which can effectively improve the situation of increased heart rate. 2. Iodine 131 treatment of hyperthyroidism usually takes 3 to 4 weeks to take effect after treatment, and the effect of some patients is even slower, and some even need 6 months to get better. So after taking iodine 131 may also be because of the effect is not yet related, just need to continue to observe. In addition, patients with severe hyperthyroidism can choose to be treated with antithyroid drugs and propranolol before drinking iodine. Any discomfort after drinking iodine should be treated at a nearby hospital.