What is postpartum thyroiditis?

Postpartum thyroiditis, or inflammation of the thyroid after giving birth, affects 10% of women.3 It often goes undiagnosed because symptoms are much like the "baby blues" that may follow delivery. Women with postpartum thyroiditis may feel very tired and moody.

Postpartum thyroiditis typically happens in two phases, though not everyone with the condition goes through both phases:

• The first phase starts 1 to 4 months after giving birth and typically last 1 to 2 months. In this phase, you may have signs and symptoms of hyperthyroidism because the damaged thyroid leaks thyroid hormones out into the bloodstream.
• The second phase starts about 4 to 8 months after delivery and lasts 6 to 12 months. In this phase, you may have signs and symptoms of hypothyroidism because the thyroid has lost most of its hormones or because the immune attack is over and the thyroid may recover later.