TSH is the abbreviation for thyrotropin, and there is no clear standard for how high it is considered serious. When TSH is higher than normal, it should be combined with other test results and patient’s symptoms to make a clear diagnosis and active treatment. The normal range of TSH is usually 0.27~4.20mIU/L, but the normal value may vary in different hospitals and different testing equipment. When TSH is elevated, it is commonly seen in primary hypothyroidism, pituitary TSH tumors, etc. How high TSH is considered serious depends on the cause of the patient’s disease, the severity of the disease, and the clinical manifestations. In addition to TSH, the diagnosis of thyroid disease also requires the combination of thyroid hormones, triiodothyronine, thyroid autoantibodies and other laboratory tests, as well as thyroid ultrasound and pituitary MRI to make a clear diagnosis. If the diagnosis is hypothyroidism, levothyroxine tablets need to be given to supplement the treatment; if the diagnosis is pituitary TSH tumor, surgery is needed. Therefore, there is no need to be overly concerned about how much TSH is considered serious, but once abnormalities are detected, it is recommended to consult a doctor in a timely manner.