Cool thyroid nodules are classified as hot nodules, warm nodules, cool nodules and cold nodules according to the difference between their location and the amount of nuclide uptake by the surrounding normal glandular tissue. It is generally believed that the possibility of cancer in “hot nodules” is very small, and the chance of cancer in “warm nodules” is also very low, but the incidence of cancer in “cool nodules” and “cold nodules” is higher, and the incidence of cancer in single nodules can reach about 20%. Therefore, the prevention of cool nodules in thyroid should be taken seriously. Preventive measures: 1. Control iodine intake: this disease is directly related to iodine, therefore, we need to pay attention to control iodine intake in our daily life, there is a certain limit of iodine intake, 120-165 micrograms for adult men and 100-115 micrograms for women, if women are in the stage of pregnancy, we need to increase about 10 micrograms as appropriate, do not eat too much iodine-rich food such as seafood, etc. etc. 2, eat more protein food: eat more protein-rich food, such as lean meat, eggs, milk, beans and so on, so that not only can supplement the body’s nutrition needs, but also improve the body’s immunity, which is also quite good for prevention. 3, exercise: usually more exercise, especially long-term office white-collar workers, more regular exercise, more exercise can improve the body’s immunity, enhance physical fitness, for the prevention of any disease are beneficial. 4, avoid stimulation: try to avoid any possible stimulation, do not eat spicy stimulating food, do not smoke and drink, and do not often irritable, angry, etc., to avoid emotional disorders caused by endocrine disorders.