What Are the Main Types of Thyroiditis?

Chronic thyroiditis

Called Hashimoto’s thyroiditis, it is by far the most common form. It begins so slowly that most people don’t know anything is wrong. Over time, the disease destroys thyroid tissue until permanent hypothyroidism results. Some patients with Hashimoto’s have normal thyroid functions (euthyroidism) with a goiter.

Subacute thyroiditis

It’s a less common form, with far fewer cases than in chronic thyroiditis. Often caused by a viral infection, the disease lasts for several months. Subacute thyroiditis is painful, causing a tender, swollen thyroid gland with pain throughout the neck. The pain usually responds to treatment with aspirin or other anti-inflammatory drugs. At first, gland destruction causes the release of stored thyroid hormones, inducing temporary hyperthyroidism. A month or two later, the patient may become hypothyroid, because the thyroid has been damaged and its hormone reserves used up. Most patients return to normal within six to nine months, but the hypothyroidism could be permanent.

Painless thyroiditis

It causes a painless swelling of the thyroid gland. When this disease occurs after pregnancy, it is called postpartum thyroiditis. The course of painless thyroiditis is otherwise similiar to painful subacute thyroiditis.

Acute thyroiditis

A rare disease, is caused by an acute infection. Patients with the disease become very sick and have a high fever. The neck is red, hot, and very tender. Acute thyroiditis is a medical emergency and must be treated with antibiotics and surgery.