The thyroid gland, a bow-tie shaped gland located at the front of the neck, produces chemicals that regulate the body's energy level. Several factors can make thyroid glands swell and they differ in varying parts of the world, reports MayoClinic.com. Many of the conditions that cause goiter, the technical name for swollen thyroid, are easily treated.
Iodine Deficiency
Lack of iodine in the diet makes thyroid glands swell. This deficiency is seen in many parts of the world, particularly mountainous regions far from the coast, reports MayoClinic.com. Iodine is found in seawater and soil close to the ocean. In iodine-deficient people, the gland swells in an effort to obtain more iodine, which is needed to produce thyroid hormones.
This rarely occurs in the United States because iodine is added to table salt.
Pregnancy
Because of increased levels of certain hormones, the thyroid gland can swell during the first trimester of pregnancy, reports"Thyroid Disease and Pregnancy." This is because it is producing too little thyroxine, a thyroid hormone. A swollen thyroid occurs more often in pregnant women who do not get enough iodine in their diet.
Hashimoto's Disease
Swollen thyroid glands are found in people with Hashimoto's disease, a condition in which the body's immune system attacks and damages the thyroid gland, reducing the production of thyroid hormone, reports MayoClinic.com. The swelling often appears after people have had the disease for some time.
Grave's Disease
Grave's disease is another disorder when people's own immune systems attack the thyroid gland. In this case, antibodies that normally protect against invading viruses or bacteria attack the thyroid gland instead, causing it to produce too much thyroid hormone and swell up.
Thyroid Nodules
Thyroid glands become swollen when people develop one or more thyroid nodules, which are fluid or solid lumps in the gland, reports MayoClinic.com. Nodules can result from a genetic defect in receptors that release the chemical that simulates the gland to produce thyroid hormone or from exposure to radiation, such as radiotherapy for a childhood cancer.
Thyroid Cancer
Thyroid glands swell if cancer is present. Thyroid cancer, however, is extremely rare compared with benign conditions that cause swelling, reports MayoClinic.com. In these cases, the swelling occurs on one side of the gland.
