Low thyroid stimulating hormone may be due to pituitary hypothyroidism, hyperthyroidism due to non-thyroid stimulating hormone tumors, as well as ingestion of aspirin, corticosteroids and intravenous heparin, etc. Consultation with a physician is recommended. TSH is the most sensitive indicator for the diagnosis of primary hypothyroidism. If it is low and accompanied by elevated thyroid hormones, hyperthyroidism may be the cause. If thyroid hormone levels are normal and only thyrotropin is low, subclinical hyperthyroidism may be the cause. Patients with hyperthyroidism may present with symptoms such as pyrexia, irritability, palpitations, and weight loss, while patients with subclinical hyperthyroidism may have no obvious clinical symptoms. It is recommended to go to the hospital and ask the doctor to make a judgment if you have low thyroid stimulating hormone.