TSH is thyroid stimulating hormone, closely related to the function of the thyroid gland and pituitary gland. High TSH means that the TSH detected in the blood is higher than the upper limit of the normal range, which may be related to hypothyroidism, subclinical hypothyroidism, pituitary tumors and other diseases or medications, and it is recommended to improve the relevant examinations to confirm the diagnosis. 1. Disease: Since TSH is secreted by the pituitary gland, pituitary hyperfunction caused by pituitary tumors and other diseases can cause high TSH; in addition, TSH is subject to the negative feedback regulation of thyroid hormones, primary hypothyroidism, subclinical hypothyroidism and other diseases can also cause high TSH. 2. Drugs: iodine-containing drugs may also cause high TSH, and the thyroid function should be checked regularly during the use of drugs. When TSH is high, the cause of the disease should be clarified under the guidance of a doctor, and active treatment should be carried out.