Thyroid Nodules and Goiter
Overview
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).
Causes
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.
Our approach to thyroid nodules and goiter
UCSF offers comprehensive consultations and treatments for thyroid conditions, including goiter (enlarged thyroid gland) and thyroid nodules. Many goiters and thyroid nodules are harmless, so we often can take a watch-and-wait approach. However, treatment may be necessary for goiters or nodules that are causing bothersome symptoms or health concerns, such as the production of too much or too little thyroid hormone. Additionally, some cases are caused by thyroid cancer, although this is rare.
Treatment options include thyroid hormone medication, radioactive iodine therapy and surgery. For patients considering surgery, UCSF offers less invasive approaches that leave either no scar or a small scar hidden under the chin.
Awards & recognition
-
Among the top hospitals in the nation
-
Best in Northern California for diabetes care & endocrinology
Signs & symptoms
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
Diagnosis
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.
Fine needle aspiration. During this test, a doctor will use a thin needle to remove a small amount of the nodule to check for cancer. If your TSH is normal or high and your thyroid nodule is more than ½-inch in diameter, you will likely need a biopsy.
Fortunately, most biopsied thyroid nodules turn out to be benign (non-cancerous) and don't require surgery. You'll just need to be checked periodically by your doctor to be sure the nodule is not growing.
For all patients with nodules or goiters, our goal is to answer the following questions in our evaluation:
1. Is the thyroid (or part of the gland) so large that it is stretching, compressing or invading nearby structures in the neck?
2. Is the thyroid working normally, or is it producing too much or too little thyroid hormone?
3. Is the goiter or nodule due to cancer?
The answers to these questions will determine the best course of treatment for you.
Treatments
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.
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.
Thyroid hormone medication (L-thyroxine)
This synthetic form of thyroid hormone can help to shrink an enlarged thyroid and treat an underactive thyroid. Hypothyroid symptoms usually start to improve within the first week of starting the medication, and disappear within a few months.
Surgery
If a goiter has become so big that it's stretching or compressing nearby structures, or if it has become unsightly, you may need surgery to remove all or part of the thyroid. Similarly, large thyroid nodules – as well as nodules that your doctor suspects may be malignant – will likely need to be removed surgically.
Thyroid surgery carries a risk of affecting the voice, because of the potential for damage to the nerves controlling the muscles that move the vocal cords. This can range from losing a high octave or two while singing, to changing the voice to a whisper.
Depending on how much of the thyroid gland is removed, you may need to take synthetic thyroid hormone for the rest of your life.
UCSF Health medical specialists have reviewed this information. It is for educational purposes only and is not intended to replace the advice of your doctor or other health care provider. We encourage you to discuss any questions or concerns you may have with your provider.
