Autoimmune Thyroid
The most common cause of an underactive thyroid is autoimmune — your immune system, not the gland itself, is the root issue. Knowing that changes how the condition should be tested and followed over time.
Overview
In Hashimoto's thyroiditis, the immune system produces antibodies that gradually impair the thyroid's ability to make hormone. It's the leading cause of hypothyroidism in iodine-sufficient countries. The process is usually slow, which is why many people have antibodies and early symptoms for years before their TSH finally drifts out of range.
Diagnosis
Hashimoto's is identified by thyroid antibodies (TPO and thyroglobulin), often alongside changes on ultrasound. Crucially, antibodies can be elevated while TSH is still 'normal' — meaning the autoimmune process is underway before standard screening flags anything. Our comprehensive panel includes antibodies specifically so we can catch this early and monitor it over time.
Management
When Hashimoto's has progressed to low thyroid output, we replace the missing hormone — with levothyroxine, desiccated thyroid, or T3/T4 combinations depending on how you respond. Beyond medication, we look at the factors that influence autoimmune activity and overall thyroid health, and we track antibodies and symptoms rather than chasing a single number.
Common Questions
Clinical references: American Thyroid Association · Endocrine Society
Keep Exploring
If you suspect Hashimoto's — or have a family history — early antibody testing and ongoing monitoring make a real difference. Book a consultation to get a complete picture.
Available across California via telehealth · in-person in Chatsworth & Santa Barbara.