A TSH blood test measures thyroid-stimulating hormone levels to assess how well the thyroid gland is functioning. It is one of the most commonly ordered tests for diagnosing thyroid disorders. Abnormal TSH levels may indicate hypothyroidism or hyperthyroidism. The test requires a small blood sample and provides valuable insights into metabolism, energy levels, and hormonal balance. TSH blood tests can be performed in labs or at home, making thyroid monitoring accessible and convenient for ongoing health management.