Thyroid Stimulating Hormone (TSH) is a pituitary hormone that regulates the production of hormones by the thyroid gland, primarily thyroxine (T4) and triiodothyronine (T3), which are crucial for metabolism, growth, and development. Abnormal TSH levels can indicate thyroid dysfunction, such as hypothyroidism or hyperthyroidism, and are commonly assessed through blood tests to diagnose and manage thyroid-related disorders.