Target organs are organs that are affected or targeted by a disease as a primary cause or by a drug to treat a disease, and these organs are called target organs. Usually, the target organs of hypertensive patients are the heart, brain, kidneys and blood vessels, i.e. for hypertensive patients, the most severely damaged organs are the heart, brain, kidneys and blood vessels, which are called the target organs of hypertensive patients. For thyroid disease, these are usually the target organs of iodine. So the target organs belong to the organs that have the greatest impact on the disease, or the organs that the drug plays a direct role in and has the most severe impact on.