Conditions: Goiter

A goiter is an enlargement of the thyroid gland that can occur with normal, high, or low thyroid hormone levels.

Goiter (also known as thyromegaly)

A goiter is an enlargement of the thyroid gland, the butterfly-shaped gland at the front of the neck, just below the Adam’s apple. The thyroid makes hormones that control how the body uses energy. A goiter simply means the gland is bigger than normal. It does not, by itself, indicate whether the thyroid is working normally, is overactive, or is underactive.

Goiters are common. They can be tiny and noticeable only on an ultrasound, or large enough to be seen and felt in the neck.

Goiters are described in several ways, and these labels are often combined (for example, a “non-toxic multinodular goiter”):

• Diffuse goiter: The whole gland is smoothly and evenly enlarged, without distinct lumps.

• Multinodular goiter: The gland contains several nodules (lumps) of varying sizes. This is one of the most common forms and becomes more frequent with age.

• Non-toxic goiter: The thyroid is enlarged but hormone levels are normal (euthyroidism). Most goiters are of this type.

• Toxic goiter: One or more parts of the gland become overactive and make too much thyroid hormone, causing hyperthyroidism (an overactive thyroid). A “toxic multinodular goiter” is a common example.

• Substernal (retrosternal) goiter: A goiter that grows downward from the neck into the chest, behind the breastbone (sternum). Because part of it sits in the chest, it can press on the windpipe or swallowing tube and may need special imaging to be seen fully.

What causes a goiter?

Several different conditions can enlarge the thyroid:

• Iodine deficiency: The thyroid needs iodine to make hormones. When the diet lacks iodine, the gland enlarges to try to keep up. This is the most common cause worldwide, though it is uncommon in countries such as the United States, where iodine is added to table salt.

• Thyroid nodules: Growths within the gland that can be single or multiple. The vast majority are not cancer. See thyroid nodules.

• Hashimoto’s (chronic lymphocytic) thyroiditis: An autoimmune condition in which the immune system slowly attacks the thyroid. It can enlarge the gland and often leads to an underactive thyroid (hypothyroidism).

• Graves’ disease: An autoimmune condition that stimulates the whole thyroid, causing diffuse enlargement together with an overactive thyroid (hyperthyroidism).

• Thyroid cancer: An uncommon cause, but one reason nodules and goiters are carefully evaluated.

• Genetics and family history: A tendency toward goiters and thyroid disease often runs in families.

• Other factors: Smoking, certain medicines, pregnancy, and shortages of nutrients such as selenium or iron can also contribute.

What problems can come from a goiter?

Many goiters cause no symptoms and are found by chance during an exam or an imaging test done for another reason. When symptoms do occur, they may include:

• A visible swelling or lump at the base of the neck.

• Compression of nearby structures, especially with large or substernal goiters. Pressure on the windpipe can cause shortness of breath, a cough, or a sensation of tightness. Pressure on the swallowing tube (esophagus) can make swallowing difficult.

• Voice changes, such as hoarseness, if the goiter affects nearby nerves. See voice conditions.

• Symptoms of an overactive thyroid (hyperthyroidism) in toxic goiters: weight loss, rapid or irregular heartbeat, tremor, feeling hot, anxiety, and trouble sleeping.

• Symptoms of an underactive thyroid (hypothyroidism), often with Hashimoto’s disease: fatigue, weight gain, feeling cold, dry skin, and constipation.

Most importantly, determining whether a goiter contains cancer is a central part of its evaluation.

What is the risk of cancer?

Most goiters and thyroid nodules are not cancer. Across large studies, only a small percentage of nodules turn out to be malignant. Ultrasound features and, when needed, a needle biopsy help identify the small number of nodules that call for closer attention. Features that raise concern include rapid growth, a hard fixed lump, persistent hoarseness, enlarged neck lymph nodes, and a history of radiation to the neck or a family history of thyroid cancer. More information is available on thyroid cancer and the Bethesda system used to classify biopsy results.

How is a goiter evaluated?

The goal of evaluation is to answer three questions: How big is the goiter, and is it pressing on anything? Is the thyroid making too much or too little hormone? Is there any sign of cancer? Common steps include:

• History and physical exam: Reviewing symptoms, family history, and iodine or radiation exposure, and feeling the neck.

• Blood tests: A TSH level is the main test of thyroid function. Other hormone levels and thyroid antibodies may be checked to look for Graves’ disease or Hashimoto’s thyroiditis.

• Ultrasound: The key imaging test. It measures the gland, counts and characterizes nodules, and identifies features that may call for a biopsy.

• Radioactive iodine uptake scan: Used mainly when the thyroid is overactive, to show whether the whole gland or specific nodules are the source of the excess hormone.

• Fine needle aspiration biopsy: A thin needle, usually guided by ultrasound, takes a small sample from a nodule to check for cancer. It is a quick office procedure.

• CT or MRI scan: Used when a goiter extends into the chest (substernal goiter), to show how far it reaches, whether it is narrowing the windpipe, and to help plan surgery. Ultrasound cannot see the part below the breastbone.

What are the treatment options?

Management ranges from observation to medication, radioactive iodine or surgery, as described on the goiter treatments page.

Key points

• A goiter means the thyroid is enlarged. It can occur with normal, high, or low thyroid hormone levels.

• Most goiters are benign, and many need only monitoring.

• Evaluation centers on blood tests, ultrasound, and, when appropriate, a needle biopsy, or a CT or MRI for goiters extending into the chest.

• Management is individualized and ranges from watchful waiting to medication, radioactive iodine, or surgery.