• If advised by your doctor, eat a special diet. Your doctor may want you on a special low iodine diet prior to the procedure. This may help your procedure to be more successful.
• Talk to your doctor about your medicines. Some thyroid hormone medicine should be discontinued four weeks before the procedure. Other medicines used to treat hyperthyroidism should be discontinued 5-7 days before the procedure.
• For two hours before the procedure, do not eat or drink anything. Water may be allowed.
• If you are a woman of childbearing age, the doctor will do a pregnancy test.
• A thyroid uptake and scan may be done before the treatment.

You will be given some tablets or liquids that contain radioactive iodine. You will swallow the tablets. The iodine will be naturally taken up by the thyroid.

At least an hour

The treatment is painless.

Any radioactive iodine that is not taken up directly by the thyroid will be passed through the urine. Be sure to follow your doctor's instructions . This may include:

• Do not eat any solid foods for at least two hours after treatment. Drink a lot of clear liquids (water or juice).
• For the first 8-12 hours following treatment, use the bathroom every hour. This will help flush the excess iodine from your body.
• Limit your contact with others. Do not enter a room with any infants or children. Stay at least three feet away from other adults. Do not stay near any other adult for more than a few minutes. Do not share a bed with anyone for 48 hours following the treatment.
• Do not share any food, drink, or dishes with anyone for the first week. Do not allow your saliva to come into contact with anyone. Avoid kissing and sexual contact.
• Flush the toilet twice after use.
• Wash hands often and thoroughly.
• Resume normal thyroid medicines 48 hours after the treatment.

The majority of people who undergo the treatment will have their thyroid levels return to normal within 8-12 weeks. However, in a small number of patients, a second dose of radioactive iodine treatment is needed.