Inflammation of the thyroid gland, causing permanent or temporary damage
Inflammation of the thyroid gland is known as thyroiditis. This disorder can disrupt thyroid activity, causing underactivity (see Hypothyroidism) or overactivity (see Hyperthyroidism) of the thyroid gland. The under- or overproduction of thyroid hormones that results is usually temporary, but it can be permanent.
Thyroiditis may take a number of different forms, depending on its cause. The three most common types of thyroiditis are described here.
The most common type of thyroid inflammation is Hashimoto’s thyroiditis, an autoimmune disorder in which antibodies are produced that attack the thyroid gland. It often causes thyroid underactivity (see Hypothyroidism) and sometimes swelling in the neck due to enlargement of the gland (see Goitre). Hashimoto’s thyroiditis is eight times more common in women and sometimes runs in families. It may occur with other autoimmune disorders, such as the skin disorder vitiligo or pernicious anaemia of the blood (see Megaloblastic anaemia).
This form of thyroiditis can sometimes be mistaken for a throat infection because it causes pain on swallowing. There may also be pain in the jaws or ears, fever, and weight loss. Viral thyroiditis can cause overactivity followed by underactivity of the gland.
About 1 in 10 women develops postpartum thyroiditis within a few months of giving birth. It is thought that this condition results from certain changes that occur in a woman’s immune system during pregnancy. Symptoms are uncommon but may include those associated with hyperthyroidism followed by those of hypothyroidism. Postpartum thyroiditis usually clears up after a few months but may recur after future pregnancies.
Your doctor may arrange for a blood test to check your thyroid hormone levels and look for specific antibodies that attack the thyroid gland. Radionuclide scanning may also be necessary to assess the level of thyroid activity.
If you have Hashimoto’s thyroiditis, you will usually need lifelong treatment with synthetic thyroid hormones (see Drugs for hypothyroidism). In severe cases of viral thyroiditis, corticosteroids or aspirin may be used to relieve the inflammation. Postpartum thyroiditis is usually temporary.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.