Thyroid Nodules and Goiter

A goiter is an enlargement of the thyroid, the H-shaped gland that wraps around the front of your windpipe, just below your Adam's apple.

A goiter can be smooth and uniformly enlarged, called diffuse goiter, or it can be caused by one or more nodules within the gland, called nodular goiter. Nodules may be solid, filled with fluid, or partly fluid and partly solid.

Thyroid nodules are quite common. When examined with ultrasound imaging, as many as one-third of women and one-fifth of men have small thyroid nodules.

It's possible for an enlarged thyroid to continue functioning well and producing the right amounts of hormones. In fact, most goiters and nodules don't cause health problems. However, goiter can also be a sign of certain conditions that cause the thyroid to produce too much thyroid hormone (called hyperthyroidism) or too little (called hypothyroidism).  

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Almost all cases of enlarged thyroid result from one of the following problems:

Inefficient Production of Thyroid Hormone

When the thyroid can't produce enough thyroid hormone, it compensates by getting bigger. Worldwide, the most common cause is not enough iodine in the diet. However, this is rare in the United States. Other causes include a genetic defect or certain medications, such as lithium carbonate.

Inflammation of the Thyroid

Common causes of an inflamed thyroid include autoimmune thyroiditis (also called Hashimoto's thyroiditis), which occurs when the person's immune system attacks its own thyroid, causing swelling and inflammation. Hashimoto's thyroiditis often results in a permanently underactive thyroid (hypothyroidism).

Another common cause is postpartum thyroiditis. This affects about 5 percent of women in the year after pregnancy. It usually goes away on its own without treatment.

Thyroid inflammation can also be caused by an infection or by certain medications.

Thyroid Tumors

Thyroid tumors are usually benign, but can be cancerous. Most tumors are nodules, but they can also appear as generalized swelling of the gland.

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Most thyroid nodules are too small to see or feel. They tend to be found when you have an imaging test done for some other reason.

A large nodule or goiter may cause a sense of tightness or pain in your neck, and can sometimes grow large enough to interfere with breathing or swallowing.

If your thyroid function is affected, you might notice other symptoms. If your gland is producing too much thyroid hormone (hyperthyroidism), you may experience:

  • Weight loss
  • Insomnia
  • Anxiety
  • Trembling hands
  • Heat intolerance

Signs that your thyroid is producing too little thyroid hormone (hypothyroidism) include:

  • Weight gain
  • Intolerance to cold
  • Muscle cramps
  • Slow thinking
  • Depressed mood

If a thyroid nodule or goiter is suspected, your doctor will examine you for signs of thyroid enlargement. Your doctor will also check to see if any lymph nodes near your thyroid are enlarged, and look for indications that you are producing too much or too little thyroid hormone. We will ask about your medical history and any symptoms you've been experiencing.

You will likely need additional diagnostic tests, which may include:

A thyroid ultrasound: This test beams sound waves into the neck to create images of the thyroid and surrounding tissues.

A blood test for thyroid-stimulating hormone (TSH): This hormone is produced by the pituitary gland and helps regulate the production of the two thyroid hormones, triiodothyronine (T3) and thyroxine (T4). The test can rule in or out common causes of hyperthyroidism and hypothyroidism.

If your TSH is low, you may have a benign thyroid tumor that is producing large amounts of thyroid hormone.

If your TSH is high, you may have an underactive thyroid gland; its enlargement may stem from inflammation caused by an autoimmune disorder.

Radionuclide thyroid scan: This test uses a radioactive tracer — which you either swallow or have injected — and a special camera to assess how your thyroid is functioning.

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Many goiters and nodules can be followed with a "watch and wait" approach. If they are causing bothersome symptoms or impacting your health, however, they will need to be treated, often with surgery. This includes cases such as:

  • Large goiters that are uncomfortable or cause difficulty with breathing or swallowing.
  • Multinodular goiters, particularly those that constrict airways, the esophagus or blood vessels.
  • Nodular goiters causing hyperthyroidism (overactive thyroid), if treatment with radioactive iodine or anti-thyroid medications are not an option.
  • Goiters or nodules that are malignant (thyroid cancer).
  • Thyroid nodules that produce uncertain results on a biopsy.

Common treatments are described below.

Radioactive Iodine

This treatment is mainly used to shrink a goiter or nodule that causes the thyroid to produce too much thyroid hormone. The iodine is given as a capsule or liquid. Once swallowed, it concentrates in the thyroid and destroys some or all of the thyroid tissue, without harming other tissues.

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