Hyperthyroidism will definitely not affect fertility after treatment with 131I, why, let’s learn more about it. This concern has two meanings: 1. whether you can have children after taking radioactive iodine; 2. whether eating radioactive iodine will affect your offspring. There are two main sources of this concern: 1. Hyperthyroidism itself is sometimes very difficult to have children. For example, women are prone to miscarriage and men are prone to impotence; 2. A few clinicians exaggerate and exaggerate. Let’s first understand what determines fertility! Fertility is determined by the female egg and the male sperm. This means that only factors that affect the egg and sperm will affect fertility. Can radioactive iodine affect eggs and sperm? Does it affect fertility? We believe that radioactive iodine does not affect fertility for several reasons: 1. Radioactive iodine only accumulates in the thyroid gland and does not travel to other tissues, much less to the female and male gonads. 2. The radiation emitted by radioactive iodine has a range of only a few millimeters in the body, so it is difficult to get from the thyroid gland to the gonads. 3. The radioactive iodine that is not taken up by the thyroid gland may be excreted in the urine, but since the amount is small and the urine is mobile, it is unlikely to affect the gonads. 4. Even so, nuclear medicine experts require patients, both men and women, to have children only six months after radioactive iodine treatment in order to be sure. In other words, if radioactive iodine has a slight effect on the eggs and sperm, the fertility can be guaranteed after six months because the metabolism of eggs and sperm is very fast. 5. A large number of foreign studies have proved that radioactive iodine treatment for hyperthyroidism has no effect on fertility. Therefore, there is no scientific basis for the claim that radioactive iodine treatment for hyperthyroidism will affect fertility.