Prior to Procedure

• 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 medications. Some thyroid hormone medications should be discontinued up to 4 weeks before the procedure. Other medications used to treat hyperthyroidism should be discontinued a minimum of 5-7 days before the procedure.
• For 2 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.

Description of the Procedure

You will be given some tablets or liquids that contain radioactive iodine. After the iodine is swallowed, it will be taken up by the thyroid.

How Long Will It Take?    TOP

At least an hour

Will It Hurt?    TOP

The treatment is painless.

Postoperative Care    TOP

Any radioactive iodine that is not taken up directly by the thyroid will be passed through the urine. Instructions may include:

• Do not eat any solid foods for at least 2 hours after treatment. Drink a lot of clear liquids, such as 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 3 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 medications 48 hours after the treatment.

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

A follow-up visit with your doctor may be scheduled 4-6 weeks after treatment. Radioactive iodine treatment can cause hypothyroidism (low thyroid function). This can occur at any time after treatment. It may be temporary or permanent. Your doctor will need to check your thyroid status every few months until levels are stable.