Radioactive iodine ablation is a proven treatment for hyperthyroidism (overactive thyroid gland), but is primarily used to treat papillary and follicular forms of thyroid cancer.
Administered in capsule or liquid form, radioactive iodine shrinks the thyroid, decreases thyroid function and eliminates thyroid cancer cells by exposing the thyroid gland to radiation. When an individual undergoes a radioactive iodine ablation, several other organs also receive exposure to radiation. Radiation exposure to other organs can produce some unwanted or unexpected side effects.
Xerostomia
Xerostomia is the medical term for dry mouth due to lack of saliva. Xerostomia is the most common side effect of radioactive iodine treatments due to the salivary glands being exposed to radiation and decreasing saliva production. Dry mouth will commonly last for over a week after a radioiodine ablation, however it will resolve naturally with time.
Nausea/Vomiting
Nausea and vomiting are also very common side effects following a radioactive iodine ablation. This occurs because the stomach and all of it's contents being directly exposed to ionizing radiation. Nausea and vomiting should resolve after a few days. Since the stomach contents receive direct exposure to radiation, any vomit produced becomes radioactive. One should realize that any person or persons involved with clean up of stomach contents will also become exposed to radiation. Precautions should be explained in detail by a physician or other healthcare personnel prior to administering a radioactive iodine ablation.
Gastralgia
Gastralgia is the medical term for stomach pain or abdominal pain. This somewhat expected side effect of radioiodine therapy results from the direct radiation exposure from ingestion of a radioactive iodine capsule or liquid. Gastralgia should resolve in a day or two.
Pain/Tenderness in Neck Organs
Due to the radiation exposure of the neck during a thyroid ablation, one may experience pain or tenderness in all neck organs. Individuals may experience pain in the thyroid bed, parotid gland (largest salivary gland), and submandibular glands (pair of salivary glands located under the floor of the mouth). Pain should subside after a day or two.
Change in taste
Because of decreased saliva production and the metallic properties of iodine, individuals may experience a temporary change in taste. This may be characterized as food not tasting as flavorful as it should. This side effect, while somewhat annoying, should resolve within 48 hours.
Fatigue
Fatigue or tiredness can also occur experience after a radioiodine thyroid ablation. This results because of a decrease in thryoid production of thyroid hormones. Fatigue is also a short term effect. Energy levels should return to normal once thyoid hormone levels return to adequate levels.
References
- Clinical Nuclear Medicine: Short Term Hazards of Low Dose Radioiodine Ablation Therapy in Post Surgical Thyroid Cancer Patients
- Thyca: Radioactive Ablation and Treatment for Papillary and Follicular Thyroid Cancer
- Journal of Nuclear Medicine: Intermediate and Long Term Side Effects of High Dose Radioiodine Therapyy for Thyroid Carcinoma
- MyThyroid: Radioactive Iodine for the Treatment of Thyroid Cancer


