Dr. Alexander Landfield
Board-Certified Neurologist & Medical Director
Millions of people suffer from thyroid-related symptoms despite being told their thyroid is normal. The problem often lies not with the thyroid itself but with how it is tested and evaluated. At Rani Beauty Clinic in Renton, WA, Dr. Alexander Landfield takes a comprehensive approach to thyroid health that goes beyond the standard TSH-only screening used by most primary care providers.
Standard thyroid testing typically consists of a single TSH measurement. If TSH falls within the laboratory reference range — usually 0.5 to 4.5 mIU/L — the patient is told their thyroid is normal. However, this approach misses several important nuances. A TSH of 3.5, while technically normal, may be suboptimal for many patients. The functional medicine optimal range for TSH is generally 1.0 to 2.0 mIU/L. Additionally, TSH alone does not reveal how much active thyroid hormone is available to cells or whether the body is converting T4 to T3 effectively.
Dr. Landfield orders a comprehensive thyroid panel that includes TSH, free T4, free T3, reverse T3, thyroid antibodies (TPO and thyroglobulin antibodies), and thyroid ultrasound when indicated. This complete picture reveals issues like Hashimoto's thyroiditis (an autoimmune condition that can cause symptoms long before TSH becomes abnormal), poor T4-to-T3 conversion, and elevated reverse T3 that blocks active thyroid hormone from reaching cells.
Treatment for suboptimal thyroid function may include thyroid hormone replacement with T4 only (levothyroxine), combination T4/T3 therapy, or desiccated thyroid hormone depending on the individual patient's lab values and clinical response. Dr. Landfield also addresses nutritional factors that impact thyroid health, including selenium, zinc, iodine, and iron levels. This holistic approach to thyroid optimization often resolves symptoms that patients have struggled with for years, including fatigue, weight gain, cold intolerance, hair loss, and brain fog.
