What is the primary function of the thyroid-stimulating hormone (TSH) test?

The thyroid-stimulating hormone (TSH) test is primarily intended to evaluate thyroid function. TSH is produced by the pituitary gland and plays a crucial role in regulating the thyroid gland's production of hormones such as thyroxine (T4) and triiodothyronine (T3). When the levels of these hormones are imbalanced, it can indicate various thyroid disorders, such as hypothyroidism or hyperthyroidism.

By measuring TSH levels, healthcare providers can determine whether the thyroid gland is functioning properly. Elevated TSH levels often suggest an underactive thyroid (hypothyroidism), while low TSH levels may indicate an overactive thyroid (hyperthyroidism). This test is a cornerstone of thyroid function testing and helps guide further diagnostic evaluations and management strategies for patients with suspected thyroid issues.

Other options relate to different systems and functions of the body. For example, assessing cardiac function, determining blood glucose levels, and measuring kidney function are unrelated to the primary purpose of the TSH test, which specifically focuses on the endocrine system and its processes.