Subacute thyroiditis (viral thyroiditis)

Subacute thyroiditis, also called viral thyroiditis, is an inflammation of the thyroid gland thought to be due to a viral infection. Signs and symptoms include:

• Enlargement of the thyroid gland, causing pain in the front of the neck
• Fever
• Fatigue
• Muscle and joint aches
• Symptoms of overactive thyroid (hyperthyroidism)

The disease usually goes away after a few months. But it may last up to six months. Initially, a person with subacute thyroiditis has signs and symptoms of hyperthyroidism, including weight loss, rapid heartbeat and anxiety. This results from excess thyroid hormone released from damaged thyroid cells. As the thyroid heals, a period of underactive thyroid (hypothyroidism) may follow.

Treatment of subacute thyroiditis may include:

• Pain relievers, such as high doses of aspirin
• Corticosteroids, such as prednisone
• During the hyperthyroid phase of the disease, drugs to block the effects of excess thyroid hormone (beta blockers)

Thyroid function typically returns to normal with no further problems. Rarely, hypothyroidism persists and requires treatment.