Your thyroid is a butterfly-shaped gland located at the base of your neck, just below your Adam's apple - about where you'd put a bow tie. Weighing less than an ounce, the thyroid gland produces hormones that regulate every aspect of your metabolism, from your heart rate to how quickly you burn calories.

Simply put, thyroid nodules are lumps which commonly arise within an otherwise normal thyroid gland. Often these abnormal growths of thyroid tissue are located at the edge of the thyroid gland so they can be felt as a lump in the throat.

Thyroid nodules are very common. A nodule is a swelling or lump, which can be a solid or liquid filled cyst or mass. Most are benign, but a small percentage can be cancerous. So you should always have a nodule evaluated by your physician as soon as you notice it. An estimated one in 12 to 15 women and one in 50 men has a thyroid nodule More than 90 percent of all thyroid nodules are not cancerous.

Thyroid Nodules Symptoms

Difficulty swallowing if the nodule is positioned such that food has difficulty traveling through the upper portion of the esophagus to the stomach

Pain is only rarely associated with thyroid nodules

In addition to these symptoms, several complications can result from a thyroid nodule. For example, a thyroid nodule may produce excessive levels of thyroid hormones (hyperthyroidism), causing symptoms such as nervousness, weight loss, and a rapid heartbeat. Diarrhea may also occur due to the hormones that are secreted by medullary thyroid cancer cells.

Causes, incidence, and risk factors:

Thyroid nodules are growths of cells in the thyroid glands. These growths can be benign (non-cancerous) or malignant (cancerous). Some nodules are fluid-filled (cysts), while others are completely made of thyroid gland cells. Sometimes, what feels like one nodule will actually be a collection of small nodules close together.

Most thyroid nodules are benign growths caused by cycles of hyperplasia (increaed cellular activity) and involution of underlying thyroid tissue. This process results in the fusion of regions of colloid-filled follicles and parenchyma, forming what is called adenomatous or colloid nodules.

Treatment

Treatment of thyroid nodules depends on the nature of the nodule as revealed by these two tests. If the nodule is "warm" and the biopsy does not show malignant cells, it can be safely assumed that the nodule is not malignant. However, if the scan shows a "cold" nodule and the biopsy shows that the cells are "suggestive of malignancy" then the nodule must be removed

Thyroid hormone therapy

If part or all of a thyroid gland is removed, hormone therapy medication is necessary to replace the thyroid gland hormones that can no longer be produced. In this case, a synthetic form of thyroid hormone must be taken daily for life. This type of hormone therapy is considered safe and causes few side effects

Thyroid scan: Your doctor may order a scan of your thyroid. You swallow a small amount of a radioactive substance, and it travels through the bloodstream. Thyroid cells that absorb the radioactive substance can be seen on a scan. Nodules that take up more of the substance than the thyroid tissue around them are called "hot" nodules. Hot nodules are usually not cancer.

You have several nodules (multinodular goiter) and surgery is not a good idea because of other health problems you have. Radioactive iodine can shrink nodules that cause problems with breathing or swallowing, but your nodules may come back after treatment.

If your thyroid nodule is causing hyperthyroidism, your doctor may recommend a dose of radioactive iodine, which usually comes in a liquid that you swallow. Your doctor may have you take medicine (antithyroid pills) for a few weeks to slow down the hormone production.