The most effective and efficient way to diagnose hypothyroidism is by measuring the thyroid stimulating hormone (TSH) level in your blood, which will be high if you have the disease. At the same time, the thyroid hormones, T4 and T3, will be low.
Other tests may be performed to determine the cause of hypothyroidism, including measuring thyroid antibody levels.
UCSF Health medical specialists have reviewed this information. It is for educational purposes only and is not intended to replace the advice of your doctor or other health care provider. We encourage you to discuss any questions or concerns you may have with your provider.