Hypothyroidism: Diagnosis...

To diagnose primary hypothyroidism, many doctors simply measure the amount of Thyroid-stimulating hormone (TSH) being produced.

High levels of TSH indicate that the thyroid is not producing sufficient levels of Thyroid hormone. However, measuring just TSH fails to diagnose secondary and tertiary forms of hypothyroidism, thus leading to a more comprehensive blood testing if the TSH is normal and hypothyroidism is still suspected.

Additionally, the following measurements may be needed:
• antithyroid antibodies - for evidence of autoimmune diseases that may be damaging the thyroid gland
• serum cholesterol - which may be elevated in hypothyroidism
• prolactin - as a widely available test of pituitary function