Hypothyroidism refers to hypothyroidism. Ultrasensitive thyrotropin 50mU/L may be hypothyroidism, and should also alert for other diseases such as simple goiter, hyperpituitary gland, and thyroid hormone resistance syndrome. Normal serum ultrasensitive thyrotropin ranges from 0.27 to 4.2 mU/L, so ultrasensitive thyrotropin 50 mU/L is significantly above the normal range and can be an important indicator for diagnosing primary or secondary hypothyroidism. For patients with hypothyroidism, thyrotropin can be lowered in the body to promote the pituitary gland to produce and release thyrotropic hormone, inducing an increase in thyrotropic hormone. In addition to hypothyroidism, some patients should also be alerted to other diseases such as simple goiter, hyperpituitarism, Hashimoto’s thyroiditis, and thyroid hormone resistance syndrome. Recent use of dopamine antagonists, iodine-containing drugs, etc., may also result in an ultrasensitive thyroid stimulating hormone of 50 mU/L and should be identified. It is recommended that the person with ultrasensitive thyroid stimulating hormone 50mU/L should undergo further detailed examination to determine whether he/she is suffering from hypothyroidism, and further treatment should be carried out under the guidance of a doctor.