Patient education: Thyroid nodules (The Basics)

What are thyroid nodules? — Thyroid nodules are round or oval-shaped growths in the thyroid gland. The thyroid gland is in the middle of the neck (figure 1).

Thyroid nodules are common and are not usually harmful to a person's health. But sometimes, thyroid nodules are caused by a serious condition, such as cancer.

The thyroid gland makes a hormone called "thyroid hormone." Most thyroid nodules do not change the amount of thyroid hormone in the body. But some cause the thyroid gland to make too much thyroid hormone. This can cause symptoms.

What are the symptoms of a thyroid nodule? — Some people do not have any symptoms. They might find out that they have a thyroid nodule when their doctor or nurse feels it during a routine exam. Or a doctor might find nodules on an imaging test that was done for another condition. (Imaging tests create pictures of the inside of the body.)

Other people have symptoms. For example, they might feel or see a lump in their neck. Or they have symptoms from having too much thyroid hormone, such as:

●Feeling worried or upset, or having trouble sleeping

●Feeling weak or tired

●Losing weight without trying

●Having a fast heartbeat

●Having frequent bowel movements

Will I need tests? — Yes. Your doctor will want to make sure that the thyroid nodule is not a threat to your health. Tests usually include blood tests and an imaging test of the thyroid called an ultrasound. Sometimes, people need more tests. These include:

●Fine-needle aspiration – During this test, a doctor uses a thin needle to remove a small sample of cells from the thyroid nodule. Then, another doctor looks at the cells under a microscope. In some cases, the cells are sent for other tests. These tests can help doctors decide which nodules should be removed by surgery and which nodules can be watched.

●Thyroid scan – People get this test only if they have too much thyroid hormone in their body. During this test, a person gets a pill or a shot with a small amount of a radioactive substance. Then, a special camera takes a picture of the thyroid gland. This test is not safe for people who are pregnant or breastfeeding.

How are thyroid nodules treated? — Thyroid nodules are treated in different ways, depending on their cause and how much thyroid hormone is in the person's body. Different treatments include:

●Watching and waiting – Doctors don't always treat thyroid nodules right away. Your doctor might watch a thyroid nodule if it is small and doesn't look serious. But they will follow it closely to see if it grows bigger or needs to be treated. This means that you might have another thyroid ultrasound and sometimes another fine-needle aspiration.

●Surgery to remove 1 or both sides of the thyroid

●Medicines – Some doctors try to shrink thyroid nodules using thyroid hormone medicines. If you take thyroid hormone medicines, your doctor or nurse will check your thyroid hormone levels regularly. This treatment is not commonly used in the US.

●Radioiodine – Radioiodine comes in a pill or liquid that you swallow. It has a small amount of radiation and can destroy a lot of the thyroid gland. It is used only to treat nodules that make too much thyroid hormone. It is not safe for people who are pregnant or breastfeeding.

●Procedure to drain fluid from the thyroid nodule – Doctors might do this if the nodule is a "cyst," which means that it is filled with fluid. After draining the fluid, they sometimes inject a substance called "ethanol" into the cyst. The ethanol causes the sides of the cyst to become stuck together. This prevents fluid from building up again.

●Radiofrequency ablation – This is a procedure that involves putting a special needle in the nodule. It uses heat to make the nodule smaller.

What if I want to get pregnant? — If you want to get pregnant, talk with your doctor or nurse. People who are pregnant should not be treated with radioiodine. That's because radioiodine can cause serious harm to a developing baby.

If you had radioiodine treatment, you will need to wait at least 6 months before trying to get pregnant. That way, your doctor can make sure that your nodule is no longer making too much thyroid hormone.

More on this topic

Patient education: Hyperthyroidism (overactive thyroid) (The Basics)
Patient education: Hypothyroidism (underactive thyroid) (The Basics)
Patient education: Thyroid cancer (The Basics)
Patient education: Seroma (The Basics)
Patient education: Thyroidectomy (The Basics)

Patient education: Thyroid nodules (Beyond the Basics)
Patient education: Hyperthyroidism (overactive thyroid) (Beyond the Basics)
Patient education: Hypothyroidism (underactive thyroid) (Beyond the Basics)
Patient education: Antithyroid drugs (Beyond the Basics)