← All conditions

Hashimoto's thyroiditis

Autoimmune hypothyroidism

Autoimmune condition

The most common cause of an underactive thyroid in the US. The immune system slowly damages the thyroid, so it makes less hormone over time.

Illustration of the thyroid gland in the neck
Illustration: Servier Medical Art, CC BY 4.0 (resized)

What happens

Immune cells and antibodies (TPO and thyroglobulin antibodies) gradually inflame the thyroid. Many people have positive antibodies for years while their thyroid levels are still normal. Over time the gland may not keep up, leading to hypothyroidism.

Who gets it

Hashimoto's is many times more common in women. It often appears between 30 and 50, and around pregnancy and perimenopause. A family history of thyroid or other autoimmune disease raises the risk.

Common signs

  • Fatigue and sluggishness
  • Feeling cold
  • Weight gain or difficulty losing weight
  • Constipation
  • Dry skin, thinning hair, or brittle nails
  • Heavier or irregular periods
  • Low mood or brain fog
  • A feeling of fullness in the neck, or an enlarged thyroid (goiter)

Labs to ask about

  • TSH
  • Free T4, and sometimes free T3
  • TPO antibodies
  • Thyroglobulin antibodies
  • Thyroid ultrasound if the gland is enlarged or a lump is felt

How it's usually treated

  • Thyroid hormone replacement (usually levothyroxine) when levels are low, adjusted with blood tests
  • Regular monitoring if antibodies are positive but hormone levels are normal
  • Closer monitoring before and during pregnancy

Supportive steps to discuss with your provider

  • Ask about selenium. Some studies show it lowers TPO antibodies, but too much is harmful, so the dose should be guided.
  • Ask to be screened for celiac disease, which is more common with Hashimoto's.
  • Check ferritin, vitamin D, and B12, which often run low.
  • Take thyroid medicine at the same time each day, apart from iron, calcium, and coffee.
  • Avoid high-dose iodine or kelp unless your provider recommends it.

See a doctor promptly if you have

  • You're pregnant or planning pregnancy and have thyroid disease or thyroid antibodies
  • A new lump, rapid neck swelling, or trouble swallowing or breathing
  • Extreme fatigue with a slow heart rate or confusion
  • Symptoms that continue despite treatment
Dr. Lesher, ND

Wondering if your symptoms fit a pattern?

Dr. Lesher is a naturopathic doctor who specializes in women's autoimmune and chronic conditions. Since 2020, she has helped more than 900 patients overcome and heal from their conditions.

Book a consult now