During postpartum thyroiditis, you might experience two phases. The inflammation and release of thyroid hormone might first cause mild signs and symptoms similar to those of an overactive thyroid (hyperthyroidism), including:
- Rapid heartbeat or palpitations
- Unexplained weight loss
- Increased sensitivity to heat
These signs and symptoms typically occur one to four months after delivery and last one to three months.
Later, as thyroid cells become impaired, mild signs and symptoms of underactive thyroid (hypothyroidism) might develop, including:
- Lack of energy
- Increased sensitivity to cold
- Dry skin
- Difficulty concentrating
- Aches and pains
These signs and symptoms typically occur four to eight months after delivery and can last from nine to 12 months.
Keep in mind, however, that some women who have postpartum thyroiditis develop symptoms of only hyperthyroidism or only hypothyroidism, but not both.
The exact cause of postpartum thyroiditis isn't clear. However, women who develop postpartum thyroiditis often have high concentrations of anti-thyroid antibodies in early pregnancy and after childbirth. As a result, it's believed that women who develop postpartum thyroiditis likely have an underlying autoimmune thyroid condition that flares after childbirth due to fluctuations in immune function. This underlying condition appears to be very similar to Hashimoto's disease, in which your immune system attacks your thyroid gland.
You might be at increased risk of postpartum thyroiditis if you have:
- An autoimmune disorder, such as type 1 diabetes
- A history of postpartum thyroiditis
- High concentrations of anti-thyroid antibodies
- A history of previous thyroid problems
- A family history of thyroid problems
While further research is needed, some studies have also shown a link between postpartum thyroiditis and postpartum depression. As a result, if you have postpartum depression your doctor will likely check to see how your thyroid is functioning.
For most women who develop postpartum thyroiditis, thyroid function eventually returns to normal — typically within 12 to 18 months of the start of symptoms. However, some women who experience postpartum thyroiditis don't recover from the hypothyroid phase. As a result, they develop hypothyroidism, a condition in which your thyroid gland doesn't produce enough of certain important hormones.
While you might not be able to prevent postpartum thyroiditis, you can take steps to care for yourself in the months after childbirth. If have any unusual signs or symptoms after childbirth, don't assume they're related to the stress of caring for a newborn. If you're at increased risk of postpartum thyroiditis, talk to your health care provider about how to monitor your health.