Thyroid nodules

What is a thyroid nodule?

Your thyroid is a small, butterfly-shaped gland at the front of your neck. A nodule is a lump of cells that grows inside it. Nodules can be solid, filled with fluid (a cyst), or a mix of both. Some people have one nodule, and others have several.

Thyroid nodules are very common and become more common with age. Many are found by chance, during a neck exam or on a scan done for another reason. More than 9 out of 10 nodules are not cancer.

What are the symptoms?

Most thyroid nodules cause no symptoms. When they do, you may notice:

• A lump you can see or feel at the front of your neck
• A feeling of pressure in your neck
• Trouble swallowing or breathing, if a nodule is large
• A hoarse voice
• Neck pain, which is uncommon

Some nodules make extra thyroid hormone. These can cause symptoms of an overactive thyroid, such as a fast heartbeat, shaky hands, sweating, or weight loss.

What causes thyroid nodules, and who is at risk?

Often there’s no clear cause. Nodules can come from an overgrowth of normal thyroid tissue, a fluid-filled cyst, Hashimoto’s disease, or low iodine in the diet. Rarely, a nodule is thyroid cancer.

Nodules are more common in women and in older adults. The chance that a nodule is cancer is higher if you:

• Had radiation to your head or neck, especially as a child
• Have a family history of thyroid cancer or certain inherited conditions
• Have a nodule that grows quickly or feels hard and fixed in place
• Have a hoarse voice or swollen lymph nodes in your neck

How are thyroid nodules diagnosed?

Your clinician will check your neck and ask about your health and family history. Tests often include:

• TSH blood test: TSH (thyroid-stimulating hormone) shows whether your thyroid is making too much or too little hormone. It’s usually the first test.
• Thyroid ultrasound: an imaging test that uses sound waves to make a picture of your thyroid. It shows each nodule’s size, whether it’s solid or fluid-filled, and features that help decide whether a biopsy is needed.
• Fine-needle aspiration (FNA) biopsy: a thin needle, guided by ultrasound, takes a small sample of cells from the nodule. It takes a few minutes, and you go home the same day. A lab looks at the cells under a microscope.
• Molecular testing: extra testing on the biopsy sample when the first result is unclear (indeterminate).
• Thyroid scan: if your TSH is low, a scan with a small amount of radioactive iodine can show whether a nodule is making extra hormone.

Not every nodule needs a biopsy. Whether a nodule needs one depends on its size and ultrasound features.

How are thyroid nodules treated?

Many nodules need no treatment, only follow-up. Options depend on what the tests show:

• Watchful waiting: repeat ultrasounds over time to check for changes, often for nodules that aren’t cancer
• Treating a nodule that makes extra hormone: with antithyroid medicines, radioactive iodine, or surgery
• Draining a cyst: removing fluid with a needle if a cyst is large or bothersome
• Surgery: removing part or all of the thyroid if a nodule is cancer, looks suspicious, or causes trouble swallowing or breathing

Some centers offer other procedures that shrink certain nodules without surgery. Ask your clinician whether one could fit your situation.

Living with thyroid nodules and when to get care

Most people with nodules that aren’t cancer simply have checkups and repeat ultrasounds on a schedule their clinician sets. Contact your clinician if:

• A nodule seems to be growing
• Your voice becomes hoarse and doesn’t get better
• You have new trouble swallowing or a feeling of pressure in your neck
• You notice signs of an overactive thyroid

When to get emergency care

Call 911 or go to the nearest emergency room if you have sudden, painful swelling in your neck with trouble breathing or swallowing.