What Is Postpartum Thyroiditis?

Medically Reviewed by Traci C. Johnson, MD on April 23, 2023
3 min read

Postpartum thyroiditis is a temporary inflammation or swelling of the thyroid gland that happens after having a baby. This causes high or low amounts of thyroid hormones, which can make you feel sick.

The thyroid is a butterfly-shaped organ in the front lower part of your neck. It makes thyroid hormones that are sent to every tissue in your body. Thyroid hormones are important and affect almost every part of your body. They help you stay warm, help you use energy, and keep your heart, brain, and muscles working.

The immune system can attack the thyroid after you have a baby and can cause the thyroid to be inflamed. This causes the thyroid to become overactive and start to send out too much thyroid hormones into your blood. This can make your body work too fast.

After some time, the thyroid will become depleted and slow down the amount of thyroid hormones it makes, which will lead to not enough thyroid hormones in the body. This is called an underactive thyroid, which will make your body work too slow. 

Experts don’t know exactly what causes postpartum thyroiditis. It is thought to be similar to Hashimoto’s thyroiditis, which is an autoimmune thyroid disease.

Postpartum thyroiditis is not very common, but some women might be more likely to get it. These include women who:

  • Have thyroid antibodies before pregnancy
  • Have had postpartum thyroiditis before
  • Have had thyroid problems before
  • Have a family history of thyroid disease
  • Have an autoimmune disease like type 1 diabetes

Postpartum thyroiditis starts with the immune system attacking the thyroid. You won’t notice until the thyroid changes how it makes hormones. The first phase is when it makes too much hormone. This causes a condition called hyperthyroidism or thyrotoxicosis. Postpartum thyroiditis symptoms include:

  • Anxiety
  • Heart palpitations
  • Irritability
  • Tiredness
  • Losing weight without trying
  • Trouble sleeping
  • Tremors
  • Nervousness
  • Sweating
  • Hyperactivity
  • Diarrhea

This phase of postpartum thyroiditis usually happens within the first four months of having your baby. During this stage, you may assume your symptoms are just part of being a new mom or the change in hormones, so the condition can be missed easily.

After this overactive stage, the thyroid can become depleted and won’t make enough thyroid hormone. This is called an underactive thyroid or hypothyroidism. This causes the body to be slow and causes symptoms, including:

  • Tiredness
  • Weight gain
  • Constipation
  • Depression
  • Dry skin
  • Feeling cold
  • Lack of energy

This phase usually happens around four to eight months after delivery and can last nine to 12 months.

Not all women go through both phases and the symptoms can also be mistaken for the stress of motherhood. Lots of women just think they’re tired because they’re awake a lot with the baby. It’s good to talk to your doctor about how you’re feeling.

If thyroid levels become too high and aren’t controlled, you could get sick with a serious, life-threatening condition called a thyroid storm. A thyroid storm is rare, but symptoms include:

  • A fast heartbeat
  • Major irritation
  • Major confusion
  • Diarrhea
  • Throwing up
  • Yellowing skin and eyes
  • High fever
  • Loss of consciousness

A thyroid storm can cause collapse and shock and is a serious medical emergency. If you feel sick or have these symptoms, you should go to your nearest hospital right away.

Postpartum thyroiditis usually doesn’t last and can clear up quickly on its own. For mild cases where hormone levels aren’t extremely high or low, you might not need any medicine. Your doctor will do some blood tests to check your thyroid stimulating hormone (TSH) levels for thyroid antibodies. Postpartum thyroiditis treatment depends on your hormone levels.

If you have major overactive thyroid symptoms and hormone levels, your doctor might give you beta blocker medicine, or prednisone steroids to help with the inflammation.

For major underactive thyroid symptoms and hormone levels, your doctor might give you a thyroid medicine called levothyroxine.

Your doctor might also tell you to take selenium or eat foods that are high in selenium. This mineral can help lower the inflammation in the thyroid.

You will need to have your blood tested regularly to make sure your thyroid hormones stay at a healthy level. If you take medicines, you will need to continue testing to see if you still need the medicine later on.

In most cases, postpartum thyroiditis clears up within 12 to 18 months and you will make a full recovery. If symptoms don’t improve, you might have permanent thyroid problems and you will need more treatment.