The thyroid gland absorbs iodine to make thyroid hormones. Using the same property, radioactive iodine also gets absorbed in remnant thyroid tissues in the thyroid bed post thyroidectomy. Since the radioactive iodine emits beta particles, it can kill those tissues. This elimination of residual thyroid is called "radioiodine therapy" or "radioiodine ablation". For this therapy, the Thyroid Stimulating Hormone (TSH) level needs to be elevated before the treatment. There are two ways to achieve this. The first is by stopping thyroid hormone supplements i.e. Tab. Thyronorm for 3-6 weeks. This starvation of thyroid hormones allows the body to raise TSH naturally and results in hypothyroidism. During hypothyroidism, the symptoms such as fatigue, mood disorder, cold intolerance, etc., may be significant. Alternatively, TSH can be increased by injecting synthetic TSH called "Recombinant human TSH (Thyrogen®)". The benefit of this is that the patient can continue taking the thyroid hormone medication and avoid possible symptoms related to hypothyroidism. However, both methods have merits and demerits of their own.