TY - JOUR T1 - Approach to a low TSH level: Patience is a virtue JF - Cleveland Clinic Journal of Medicine JO - Cleve Clin J Med SP - 803 LP - 811 DO - 10.3949/ccjm.77a.10056 VL - 77 IS - 11 AU - Kevin M. Pantalone AU - Christian Nasr Y1 - 2010/11/01 UR - http://www.ccjm.org/content/77/11/803.abstract N2 - Confronted with a low serum level of thyrotropin (thyroid- stimulating hormone, TSH), physicians should not jump to the conclusion that it is due to a hyperthyroid state, as other conditions and some drugs can be associated with a TSH level that is slightly low (0.1–0.4 μIU/mL) or frankly suppressed (< 0.1 μIU/mL). This review discusses how to approach a low TSH, stressing the frequent need to reassess thyroid function before making a diagnosis, the underlying processes and the drugs that can be responsible, and the degree of TSH suppression and its role in the evaluation. ER -