Hyperthyroidism Slideshow Pictures Take the Thyroid Disorder Quiz Thyroid Symptoms and Solutions Slideshow Pictures

Medical Author:

Stephanie L Lee, MD, PhD, FACE

Coauthor:

Sonia Ananthakrishnan, MD

Medical Editor:

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

View Full Profile

Hypothyroidism Diagnosis

The history and physical examination generally reveal the characteristic symptoms and physical signs that suggest hypothyroidism; however, laboratory evaluation is necessary to establish the diagnosis and cause of hypothyroidism.

Diagnostic lab tests include measuring the blood levels of:

• Thyroid stimulating hormone (TSH). This hormone will be elevated in cases of hypothyroidism. The TSH assay is the most sensitive test for the diagnosis of hypothyroidism.
• Free T4 (free thyroxine) and T3 thyroid hormones. Thyroid hormone levels in the blood will be low, but with mild, or "subclinical" hypothyroidism, the thyroid hormone levels can be in the low normal range.
• Thyroid autoantibodies (anti-thyroid peroxidase and antithyroglobulin autoantibodies). The presence of these antibodies indicates autoimmune thyroiditis (Hashimoto's disease) as the underlying cause of hypothyroidism.