Radioactive iodine treats hyperthyroidism by destroying all or part of the thyroid gland, according to WebMD. The patient swallows a single dose of the radioactive medication, and the thyroid absorbs it from the bloodstream. The size of the dose determines the amount of thyroid tissue it destroys. The medication does not affect other tissue or cause thyroid cancer.
Most patients do not notice any difference after treatment with radioactive iodine, although some experience nausea, warns WebMD. After the iodine does its job, the body eliminates it through the saliva and urine. The time the body requires for this depends on the size of the dose and the age of the patient. Younger patients tend to eliminate it sooner than older ones do.
Radioactive iodine is generally safe and offers the best chance of curing hyperthyroidism permanently. Millions of patients have received radioactive iodine therapy for more than 60 years, claims WebMD. It is often used in cases where antithyroid medication or thyroid surgery are not effective. For most patients, the thyroid levels return to normal within 12 weeks of taking the medication.
Patients who take radioactive iodine must take special precautions to prevent the radiation from harming others, warns WebMD. They should follow their doctor’s orders for maintaining a safe distance from others, especially children. The medication is likely to set off airport radiation detectors if patients attempt to travel within a few days after taking it.