Medically Reviewed by Michael Dansinger, MD on November 06, 2022
4 min read

Thyroiditis is a swelling of your thyroid gland. It mostly affects women from early adulthood to middle age, but anyone can get it.

The thyroid is the butterfly-shaped gland in the front of your throat, just below your Adam’s apple. It controls your metabolism by making hormones that influence how fast or slow your heartbrain, and other parts of your body work.

There are different types of thyroiditis, but they all cause inflammation and swelling of your thyroid. They can make it produce too many or not enough hormones. Too many can make you feel jittery and possibly make your heart race. Too few and you may feel tired and depressed.

About 20 million Americans have a form of thyroid disease. Like the others, thyroiditis can be a serious illness. Treatment will depend on the type you have and the symptoms it causes. 

Thyroiditis phases

Thyroiditis has three phases:

  • Thyrotoxic phase. The thyroid is swollen and releases too many hormones.
  • Hypothyroid phase. After a few weeks or months, too much of the thyroid hormone is released and leads to hypothyroidism, when you don’t have enough left.
  • Euthyroid phase. In this phase, thyroid levels are normal. It can happen between the first two phases or at the end, after the swelling has gone down.

Common symptoms include fatigue, swelling at the base of your neck, and sometimes some pain in the front of your throat

However, other symptoms will vary, depending on whether your thyroid is underactive (hypothyroidism) or overactive (hyperthyroidism).

Symptoms of hypothyroidism may include:

Symptoms of hyperthyroidism may include:

Many things can make your thyroid swell. You may have gotten an infection from a virus or bacteria. You may be taking a drug like lithium or interferon. Or you may have problems with your immune system.

One form of thyroiditis shows up after childbirthPregnancy has a major impact on the thyroid in general.

These are the most common causes:

  • Hashimoto's disease. This is the most common type of thyroiditis. Your immune system attacks your thyroid and slowly weakens the gland until it can’t make enough thyroid hormones.
  • Subacute thyroiditis. This type is often triggered by an infection. There’s usually a pattern of how the thyroid functions. First, the thyroid and neck area are painful. Then, the thyroid makes too much hormone, called hyperthyroidism. Then, your thyroid works normally, followed by a time where the thyroid produces too little thyroid hormone. This is called hypothyroidism. After about 12 to 18 months, thyroid function returns to normal.
  • Postpartum thyroiditis. This type begins within a year after childbirth, particularly in women with a history of thyroid issues. With treatment, the thyroid usually recovers within 18 months.
  • Silent thyroiditis. As the name suggests, there are no symptoms with this type. It’s similar to postpartum thyroiditis, and recovery usually takes up to 18 months. It starts with a phase of too much hormone production, followed by a longer period of the thyroid making too little.


Your doctor may give you one or more of these tests.

  • Blood test. Thyroid hormones circulate in your blood, and their levels can help your doctor figure out the specific kind of thyroiditis you have.
  • Radioactive iodine uptake test (RAIU). Because iodine collects in your thyroid gland, a doctor or nurse gives you radioactive iodine as a pill or liquid. Over the next 24 hours, your doctor will check at several points to see how much iodine your thyroid has absorbed.
  • Thyroid scan. You get a shot of radioactive iodine. You lie faceup on a table with your head bent back, exposing your neck. Your doctor uses a device to take images of your thyroid.
  • Erythrocyte sedimentation rate (ESR or sed rate). This test measures swelling by how fast your red blood cells fall. High ESR may mean you have subacute thyroiditis.
  • Ultrasound. A sonogram of your thyroid can show a nodule or growth, a change in blood flow, and the texture or density of the gland.

Treatment depends on the type of thyroiditis you have.

Doctors usually treat hypothyroidism with synthetic versions of thyroid hormone. They come in pills that you swallow. As your metabolism returns to normal, your doctor may adjust the dosage.

The treatment of hyperthyroidism depends on the type of inflammation and on any symptoms you have.

Beta-blockers often treat symptoms like a fast heart rate and palpitations. Antithyroid medicines can lower the amount of hormones that your thyroid is making. Sometimes, your doctor may prescribe a form of radioactive iodine to shrink the thyroid and reduce any symptoms.

If you have thyroid pain, your doctor may recommend nothing more than aspirin or ibuprofen. Severe pain may be treated in other ways.

It’s rare, but you may need surgery if other treatments don’t work.