TSH level is the measured concentration of thyroid-stimulating hormone in the blood, produced by the pituitary gland to regulate thyroid hormone production. Normal TSH levels indicate that the feedback loop between the pituitary and thyroid is functioning properly, while elevated or suppressed levels signal potential hypo- or hyperthyroidism, respectively. TSH testing is often the first-line screening tool for thyroid disorders and is commonly monitored in patients taking thyroid replacement or antithyroid medications. Because thyroid function affects metabolism, energy, heart rate, and weight, TSH levels can provide underwriters with valuable information about an applicant's endocrine stability and overall health.

Advisors see TSH levels in lab reports requested during underwriting, particularly when clients disclose thyroid medications or symptoms like fatigue and weight gain. Underwriters prefer TSH levels within or near target ranges, with a clear treatment history and consistent follow-up. Abnormal or widely fluctuating TSH values may prompt further questions, additional labs, or postponement until control is documented. Advisors help clients understand why the carrier cares about TSH and encourage regular checkups to maintain stable thyroid function. Understanding TSH level allows advisors to interpret lab summaries more confidently and to anticipate underwriting outcomes for clients with thyroid issues.