Thyroid Nodules: Symptoms, Causes & Treatment

Thyroid nodules are small lumps that develop in the thyroid gland. Although most thyroid nodules are benign, some can produce excess thyroid hormones or, in some cases, be a sign of thyroid cancer.

Many thyroid nodules do not cause symptoms, but larger nodules may lead to a lump in the neck, swelling, hoarseness, or difficulty swallowing or breathing. A healthcare provider can diagnose thyroid nodules with a physical exam, thyroid ultrasound, and, in some cases, a fine-needle aspiration biopsy.

Treatment for thyroid nodules depends on their size, symptoms, and whether they are benign or cancerous. Options may include regular ultrasound monitoring, thyroid hormone replacement, antithyroid medication, radioactive iodine treatment, or surgery.

Main symptoms

The main signs and symptoms of thyroid nodules include:

• A lump in the neck

• Sore throat

• Swelling or a feeling of pressure in the neck

• Difficulty breathing or swallowing

• Hoarseness or other changes in the voice

Some thyroid nodules produce excess thyroid hormones, such as T3 and T4. This can lead to hyperthyroidism, which occurs when there are too many thyroid hormones in the bloodstream.

Low thyroid hormone levels may also occur in people with thyroid nodules, although this is usually caused by an underlying thyroid condition rather than by the nodule itself.

According to the American Thyroid Association, most thyroid nodules do not cause symptoms and are often discovered during a routine physical exam or incidentally on an imaging test, such as a neck ultrasound or CT scan.

Signs that it might be cancer

Signs that may suggest a higher risk of thyroid cancer include a nodule larger than 4 cm, a hard nodule, limited movement, swollen lymph nodes in the neck, hoarseness, or other voice changes.

The risk may also be higher in older adults, people with a family history of thyroid cancer, and those who have had radiation exposure to the head or neck, such as from radiation therapy.

Confirming a diagnosis

A thyroid nodule is diagnosed by an endocrinologist or primary care provider based on a physical exam and imaging test results.

During the physical exam, a healthcare provider feels the neck to check for lumps or changes in the thyroid gland. A thyroid ultrasound can then be used to confirm the presence of a nodule and assess its characteristics.

Depending on how the nodule looks on the ultrasound, the provider may recommend additional tests. According to the National Institute of Diabetes and Digestive and Kidney Diseases, a fine-needle aspiration biopsy may be used to determine whether a thyroid nodule is benign or cancerous by collecting small tissue samples for laboratory analysis.

What is the normal size of a thyroid nodule?

There is no normal size for a thyroid nodule. However, nodules smaller than 1 cm often do not require further testing unless they have suspicious features on ultrasound or are associated with other risk factors.

Even small thyroid nodules may need additional evaluation depending on their appearance on ultrasound.

When is a thyroid nodule considered large?

Although there is no strict size limit, thyroid nodules larger than 2 cm may be considered large.

Additional tests may be needed to evaluate these nodules because of the possible risk of thyroid cancer.

Possible causes

Thyroid nodules may be caused by:

• An overgrowth of normal thyroid cells

• A thyroid cyst

• Chronic inflammation of the thyroid gland

• Thyroid cancer

The risk of developing thyroid nodules may also be higher in people with a history of radiation exposure to the neck, such as radiation therapy. Other possible risk factors include obesity, smoking, metabolic syndrome, and excessive alcohol consumption.

It is important to distinguish thyroid nodules from other causes of neck lumps, such as swollen lymph nodes and lipomas. An accurate diagnosis allows the doctor to recommend the most appropriate treatment.

Treatment options

Benign thyroid nodules may only require regular monitoring with thyroid ultrasounds. These exams are usually performed every 12 to 24 months to check whether the nodule has grown or changed.

If a nodule develops suspicious characteristics on an ultrasound, a doctor may recommend a fine-needle aspiration biopsy to check for cancer cells.

Thyroid surgery may be recommended for cancerous nodules, nodules larger than 4 cm, or nodules that cause symptoms because of their size. These symptoms may include neck pain or difficulty swallowing.

If thyroid hormone levels are abnormal, the doctor may prescribe treatment to restore them to a healthy range. Thyroid hormone replacement may be recommended for low hormone levels, while antithyroid medication or radioactive iodine may be used for high hormone levels.

Is there medication that can dissolve a thyroid nodule?

There is no medication that can dissolve a thyroid nodule.

However, radioactive iodine treatment may help shrink certain nodules that produce excess thyroid hormones.

Thyroid nodules and pregnancy

Women with thyroid nodules are generally no more likely to have difficulty becoming pregnant than women without nodules.

However, some thyroid nodules can affect thyroid hormone production. If hormone levels become abnormal, a healthcare provider may prescribe medication to help regulate thyroid function.