This form is called postpartum thyroiditis. In other individuals, a viral infection in the thyroid gland can cause a disease called subacute thyroiditis, which is one of the very few conditions that causes pain in the thyroid gland. Unlike Graves' disease, the hyperthyroidism that occurs with postpartum and subacute thyroiditis resolves itself in a few weeks. Sometimes a temporary period of hypothyroidism occurs after a bout of postpartum or subacute thyroiditis. In younger people, a goiter, or enlarged thyroid gland, is most commonly caused by some form of thyroiditis.
Goiters usually develop over many months or years.
In most cases the thyroid continues to function normally, meaning that hypothyroidism or hyperthyroidism are not present. Nodules in the thyroid gland are common in both younger and older individuals. Fortunately, most are just benign growths that are not a cause of great concern. If you and your doctor suspect that you have an underactive or overactive thyroid gland, blood tests are the best way find out for sure. In hypothyroidism, the level of T4 in the blood is usually below normal, whereas in hyperthyroidism both T4 and T3 levels are usually elevated.