What are thyroid nodules?

Thyroid nodules are growths or lumps in the thyroid gland gland in the front of your neck. This gland controls how your body uses energy. Most thyroid nodules are not cancer and do not cause problems. Many don’t even need treatment.

Once in a while, a thyroid nodule can cause problems. Sometimes a nodule can make too much thyroid hormone. When a nodule makes too much hormone, the rest of the gland is suppressed and actually doesn't work as hard as usual.

Only about 5 out of 100 thyroid nodules are cancer.¹ In these cases, surgery to remove the nodule is necessary.

What causes thyroid nodules?

It is not clear what causes thyroid nodules. But people who have been exposed to radiation have a greater chance of getting them. Also, the nodules tend to run in families. So if your parents had thyroid nodules, you are more likely to have one.

What are the symptoms?

Most thyroid nodules are so small that you don’t even know you have one.

If you have a big nodule, you may be able to feel it, or you may notice swelling in your neck. It’s possible that you may also:

• Feel pain in your throat or feel like your throat is full.
• Have a hard time swallowing.
• Have trouble breathing.
• Feel nervous, have a fast heartbeat, sweat a lot, or lose weight. These are symptoms of hyperthyroidism, where the thyroid gland makes too much thyroid hormone.
• Feel tired or depressed, have memory problems, be constipated, have dry skin, or feel cold. These are symptoms of hypothyroidism, where the thyroid gland does not make enough thyroid hormone.

How are thyroid nodules diagnosed?

Most people don’t find thyroid nodules on their own, because the nodules aren't easy to feel and don’t usually cause symptoms. Your doctor may have found a nodule on your thyroid when you were having a CT scan or ultrasound for another reason. Your doctor will do a physical exam and will ask you if you have symptoms or any changes in how you've been feeling.

You may have tests to see how well your thyroid is working and to make sure the nodule is not cancer. Possible tests include:

• A blood test to check the level of thyroid hormone in your body.
• A thyroid scan, which uses radioactive material and a camera to see how well your thyroid gland is working. This is done if the level of thyroid hormone is high.
• Thyroid ultrasound, to see the number and size of nodules, or biopsy, to check the nodule for cancer.

How are thyroid nodules treated?

If your nodule is not cancer and is not causing problems, your doctor may watch your nodule closely.

If your thyroid nodule is causing hyperthyroidism, your doctor may recommend a dose of radioactive iodine, which usually comes in a liquid that you swallow. Your doctor may have you take medicine (antithyroid pills) for a few weeks to slow down the hormone production. Your thyroid hormone level needs to be normal before you can be treated with radioactive iodine.

If your nodule is cancer or is so large that it causes problems with swallowing or breathing, you'll need surgery to remove the nodule. You may also need treatment with radioactive iodine to destroy any leftover cancer cells. After surgery, you may need to take thyroid medicine for the rest of your life.

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