131 generally refers to iodine 131 treatment. How long you can go to work after having iodine 131 treatment is related to the dosage of iodine 131 used, and you can go to work after 3 to 12 days of isolation is generally required. When the dosage of iodine 131 is 1.85GBq, you can usually go to work after 3 days; when the dosage of iodine 131 is 3.70GBq, you can go to work after 7 days; when the dosage of iodine 131 is 5.55GBq, you can go to work after 10 days; when the dosage of iodine 131 is 7.40GBq, you can go to work after 12 days. Necessary and appropriate living isolation after iodine 131 treatment is an integral part of the treatment process, and it is important for patients to follow the doctor’s instructions for proper isolation after taking iodine 131 in order to protect family members as well as the public.