Thyroid Nodules

Topic Overview

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.

Frequently Asked Questions

Cause

Experts do not know the exact cause of thyroid nodules. But they do know that people who have been exposed to radiation have a greater chance of developing thyroid nodules. Exposure to environmental radiation or past radiation treatment to the head, neck, and chest (especially during childhood) raises your risk for thyroid nodules.

Experts know that thyroid nodules run in families. This means you are more likely to have a thyroid nodule if one of your parents has had a thyroid nodule.

Also, if you have another thyroid condition (such as goiter), you may have a greater chance of developing thyroid nodules.

Symptoms

Most thyroid nodules do not cause symptoms and are so small that you cannot feel them. They often are found during a physical exam or when another test, such as a CT scan or ultrasound, is done for a different reason.

If your thyroid nodule is big, you may be able to feel it or you may notice that your neck is swollen. In rare cases, you may also:

• Feel pain in your throat or feel like your throat is full.
• Have a hard time swallowing.
• Have a hard time breathing.
• Feel nervous, have a fast heartbeat, sweat a lot, lose weight, or have other symptoms of hyperthyroidism (too much thyroid hormone).
• Feel tired or depressed, have memory problems, be constipated, have dry skin, feel cold, or have other symptoms of hypothyroidism (too little thyroid hormone).

A biopsy is the only way to tell if a thyroid nodule is cancerous. But cancer may be more likely if you have:

• A single, hard lump that feels very different from the rest of the thyroid tissue or other thyroid nodules.
• A nodule that keeps growing for weeks or months.
• A nodule that does not move when you touch it.
• Swollen lymph nodes in your neck.
• A hoarse or scratchy voice that does not go away.

Some other conditions that cause similar symptoms include hyperthyroidism and thyroiditis.

What Happens

Most thyroid nodules do not cause problems and are not cancerous. They are often hard to notice because they are so small. Lots of people have thyroid nodules that are never found or treated.

There are three kinds of thyroid nodules: solid nodules, nodules that are filled with fluid (cystic nodules), and nodules that are partially cystic. You can have one thyroid nodule or several thyroid nodules (multinodular goiter). You can also have some nodules that are solid and some that are cystic. Solid nodules may grow slowly over time. In rare cases, cystic nodules bleed, which can cause them to grow suddenly and become painful.

Thyroid nodules usually do not prevent the thyroid gland from doing its job. But sometimes a noncancerous thyroid nodule can cause:

• Hyperthyroidism. Hyperthyroidism happens when one or more nodules makes too much thyroid hormone. Hyperthyroidism is treated with antithyroid medicine, possibly radioactive iodine, and very rarely, surgery. Hyperthyroidism from thyroid nodules is not very common: it occurs in fewer than 1 out of 100 people who have thyroid nodules.² For more information on treating hyperthyroidism, see the topic Hyperthyroidism.
• Difficulty breathing or swallowing. Sometimes, one or more large nodules can press on your windpipe (trachea) or on your esophagus. These kinds of nodules have to be surgically removed.

Only about 5 out of 100 thyroid nodules are cancerous.¹ Thyroid cancer is usually diagnosed and treated early, so most people do very well. For more information, see the topic Thyroid Cancer.

What Increases Your Risk

You are more likely to develop a thyroid nodule if:

• You are older. Thyroid nodules are more common in older people.
• You are female. Women are more likely than men to develop thyroid nodules.
• You have been exposed to radiation. Exposure to environmental radiation or past radiation treatment to your head, neck, and chest (especially during childhood) increases your risk for thyroid nodules.
• You do not get enough iodine. Iodine deficiency is rare in the United States but it is common in areas where iodine is not added to salt, food, and water. An iodine deficiency may result in an enlarged thyroid gland (goiter ), with or without nodules.
• You have Hashimoto's thyroiditis. Hashimoto's thyroiditis can cause an underactive thyroid gland (hypothyroidism).
• One or both of your parents have had thyroid nodules.

Most thyroid nodules are not cancerous. But a nodule is more likely to be cancerous if:

• You have had radiation treatment, or were exposed to radiation in the environment. In rare cases, thyroid cancer could appear up to 20 years after radiation exposure.
• You have family members who have had cancer in their endocrine glands, including the thyroid gland.
• You are younger than 30 or older than 60.
• You are male.
• The nodule grows quickly over a period of weeks or months. However, just because a nodule has changed in size does not mean it is cancerous.
• You develop a nodule while you are pregnant.
• You have Graves' disease.
• You have Hashimoto's thyroiditis.

When To Call a Doctor

Call your doctor if you have any of these signs of thyroid nodules:

• Swelling in your neck for more than 2 weeks
• A hoarse or scratchy voice that is not caused by a cold or throat infection and lasts longer than 1 month
• A hard time swallowing
• Symptoms of a thyroid problem such as feeling tired, weak, or nervous, losing weight, having trouble sleeping, or having a fast heartbeat

If you have had part of your thyroid gland removed because of noncancerous thyroid nodules, you will need regular medical checkups to make sure your thyroid gland is working well.

Watchful Waiting

For some kinds of health problems, you can wait and see what happens for a while before you and your doctor decide what kind of treatment you should have. This is called watchful waiting. Because of the small risk of cancer, watchful waiting is not recommended for people with thyroid nodules.

Call your doctor if you have swelling in your neck that does not go away, problems swallowing, a hoarse or scratchy voice that has lasted several weeks, or any other symptoms of a thyroid problem.

Who To See

Different types of health professionals can help treat a thyroid problem.

• Family medicine doctor or general practitioner
• Internist
• Pediatrician
• Nurse practitioner
• Physician assistant

Your doctor may also refer you to an endocrinologist for further tests and treatment.

If you need a special exam or treatment, you may see one of these types of doctors:

• Nuclear medicine physician (a doctor who specializes in medicine using different types of radioactive substances)
• Surgeon
• Otolaryngologist (an ear, nose, and throat specialist)

To prepare for your appointment, see the topic Making the Most of Your Appointment.

Exams and Tests

The first step in diagnosing thyroid nodules is a medical history and physical exam. Thyroid nodules often are found during a physical exam or during a CT scan or ultrasound of the neck, chest, or head done for another problem. Most people do not find thyroid nodules on their own because they are difficult to feel and usually do not cause symptoms.

If your doctor finds a thyroid nodule, he or she may refer you to an endocrinologist for more tests and treatment.

Common tests for people with thyroid nodules are:

• Thyroid-stimulating hormone (TSH) test. This is a blood test to see how well your thyroid gland is working.
• Thyroid biopsy. This test checks to see if your nodule is cancerous. A biopsy involves removing a piece of your thyroid nodule, often through a needle. This test is a simple procedure that can be done in your doctor's office.
• Thyroid ultrasound. Ultrasound uses reflected sound waves to create a picture of organs and other structures inside your body. Ultrasound cannot determine whether a nodule is cancerous, but it can help your doctor:
  • Confirm that you have thyroid nodules if other tests have not been clear.
  • See what is happening to nodules that are not going away.
  • Find your nodule during a thyroid biopsy done with a needle.

Other tests you may have include:

• Thyroid hormone tests. These blood tests are done to see if a nodule is causing your thyroid gland to make too much or too little thyroid hormone.
• Calcitonin test. This test checks your level of a hormone called calcitonin as a way to help find out if you have cancer. This test will probably be done if other people in your family have had thyroid cancer or any other type of cancer of the endocrine glands.
• Thyroid scan. This test uses radioactive material and a camera to see how well your thyroid gland is working and to see if you have hyperthyroidism.

Ongoing exams

If your nodule is not cancerous, your doctor will check its size once a year. He or she may also do a thyroid-stimulating hormone (TSH) test to see how well your thyroid is working. An ultrasound may also be used to see if your thyroid nodule has grown. If your nodule has gotten bigger, another biopsy, and surgery, may be necessary.

If your thyroid gland was removed because of cancer, your doctor may test for thyroglobulin, a protein made by both normal and cancerous cells. High levels of thyroglobulin may mean that the cancer has spread (metastasized) to other parts of your body.

Treatment Overview

Your treatment will depend on how your thyroid nodule affects you. If your thyroid nodule is not cancerous (benign) and is not causing any problems, your doctor will watch the nodule closely before doing anything else. If your thyroid nodule is causing problems, you may need to take medicine or have surgery.

Antithyroid medicine and radioactive iodine can treat benign nodules that are causing your thyroid gland to make too many hormones (hyperthyroidism). For more information on hyperthyroidism, see the topic Hyperthyroidism.

Surgery is usually only necessary if your thyroid nodule is so large that it causes problems with breathing or swallowing or if your nodule is cancerous. After a cancerous nodule is surgically removed, you may need radioactive iodine to destroy any thyroid tissue or cancer cells that are still causing problems. If you need to have your entire thyroid gland removed, you will need to take thyroid hormone medicine for the rest of your life.

For information about thyroid cancer and its treatment, see the topic Thyroid Cancer.

Initial treatment

When you know you have a thyroid nodule, your treatment options include:

• Observation. If your thyroid nodule is not cancerous, your doctor may choose to check it every 6 to 12 months for changes in size. Many noncancerous thyroid nodules stay the same size or shrink without treatment.
• Thyroid biopsy. Your doctor may drain a fluid-filled nodule with a needle. Some fluid-filled nodules will not come back after they are drained, but most do come back.
• Surgery (thyroidectomy). Not all thyroid nodules need surgery. You will need to have surgery to remove part or all of your thyroid gland if:
  • Your nodule is cancerous or suspected to be cancerous.
  • Your nodule is so big that it makes it hard for you to breathe or swallow.
  • You have a fluid-filled nodule that returns after being drained one or two times.
• Thyroid-stimulating hormone (TSH) suppression therapy may be used to shrink a nodule if:
  • Your thyroid nodule is not cancerous, but is large or growing, or if you have a goiter and multiple nodules.
  • Your thyroid nodule is cancerous or suspected to be cancerous, and you are not healthy enough to have surgery.
• Radioactive iodine. Radioactive iodine may be used to destroy thyroid tissue if:
  • Your nodule is noncancerous but is making too much thyroid hormone, causing hyperthyroidism. If you have hyperthyroidism because of your nodule and you are pregnant, it is not a good idea to have radioactive iodine treatment. Your doctor will recommend surgery instead of radioactive iodine.
  • You have several nodules (multinodular goiter) and surgery is not a good idea because of other health problems you have. Radioactive iodine can shrink nodules that cause problems with breathing or swallowing, but your nodules may come back after treatment.

Ongoing treatment

If your doctor is observing your thyroid nodule and there is no change in it, he or she may just continue to watch the nodule. If the nodule changes in size or in other ways, your doctor may do another thyroid biopsy and blood tests for thyroid-stimulating hormone (TSH), or perform surgery (thyroidectomy) to remove the nodule.

If part or all of your thyroid gland needs to be surgically removed because of cancer, radioactive iodine may be used to destroy any thyroid tissue or cancer cells that remain after surgery. Your doctor may also recommend thyroid-stimulating hormone (TSH) suppression therapy to prevent thyroid nodules from coming back.

If you have a thyroid nodule, it is important to:

• Take any thyroid hormone medicine your doctor prescribes at the same time each day and do not miss a dose.
• Follow your doctor's recommendation for getting your blood checked for thyroid level.
• Call your doctor if you have symptoms of hyperthyroidism, such as feeling nervous, having a fast heartbeat, sweating more than usual, and losing weight. Sometimes hyperthyroidism develops from taking thyroid hormone medicine or when a noncancerous nodule starts making too much thyroid hormone.
• Call your doctor if you have symptoms of hypothyroidism, such as feeling tired, feeling cold when others do not, and gaining weight. Hypothyroidism can develop after you are treated with radioactive iodine or you have surgery.
• Schedule regular checkups with your doctor. Even noncancerous nodules need to be looked at by your doctor on a regular basis.

Treatment if the condition gets worse

If your thyroid nodule gets bigger, your doctor may recommend another thyroid biopsy to see whether the nodule has become cancerous. If your nodule has become cancerous or appears to be cancerous, your doctor will probably recommend surgery (thyroidectomy) to remove some or all of your thyroid gland. You may also need thyroid-stimulating hormone (TSH) suppression therapy and/or radioactive iodine.

What To Think About

It is not clear how well thyroid-stimulating hormone suppression therapy works to shrink noncancerous thyroid nodules. If you have a noncancerous nodule, talk to your doctor about whether TSH suppression therapy is right for you.

TSH suppression therapy can raise your risk of heart and bone problems, especially if you have heart disease or osteoporosis. If you have heart disease, this kind of medicine can make chest pain or problems with your heart rhythm worse. It can also raise your chances of heart attack. If you have osteoporosis, TSH suppression therapy can further weaken your bones.

Surgery is the best treatment for cancerous thyroid nodules. If you have a suspicious nodule, you can often wait a while to have surgery because most thyroid cancers grow and spread very slowly. If you choose to delay surgery, your doctor will need to closely watch your nodule.

Prevention

Thyroid nodules cannot be prevented.

It is not clear whether people who do not have any risk factors and who do not have any symptoms of hyperthyroidism need to be tested regularly for thyroid problems. The American Thyroid Association recommends that adults, particularly women, be screened for thyroid problems every 5 years, beginning at age 35. But the U.S. Preventive Services Task Force does not think there is enough evidence to recommend either for or against regular thyroid testing. Talk to your doctor about whether you need to be tested for thyroid problems.

Home Treatment

Most thyroid nodules are not cancerous. Many thyroid nodules do not need medical treatment. If you have a thyroid nodule that is being watched, schedule regular medical checkups to see whether there are any changes.

If you have had surgery to remove your thyroid gland, it is important to:

• Take your medicine at the same time each day and do not miss a dose.
• Take only your regular dose, even if you miss a dose. Do not "double up" the next day.
• Call your doctor if you have symptoms of hyperthyroidism such as feeling nervous, having a fast heartbeat, sweating more than usual, and losing weight.
• Ask your doctor or pharmacist if your thyroid medicine can be safely mixed with other prescription or nonprescription medicines you take.

If you have had radioactive iodine treatment for thyroid nodules, call your doctor if:

• You have neck pain. This may mean your thyroid gland is swollen.
• You have symptoms of hypothyroidism, such as feeling tired, feeling cold when others do not, and gaining weight.

Medications

Sometimes doctors treat thyroid nodules with thyroid-stimulating hormone suppression therapy (levothyroxine) to stop the body from making thyroid-stimulating hormone (TSH) and prevent growth in the thyroid gland. Your doctor may recommend TSH suppression therapy if:

• You are not healthy enough to have surgery and you have thyroid cancer or a nodule that is suspected to be cancerous.
• You had surgery to remove part of your thyroid gland because of multiple thyroid nodules. Sometimes, TSH suppression therapy is used after surgery to help prevent your nodules from coming back.

Medication Choices

Thyroid-stimulating hormone (TSH) suppression therapy, such as levothyroxine sodium (for example, Synthroid, Levoxyl, or Levothroid), liothyronine sodium (for example, Cytomel), liotrix (Thyrolar), or desiccated thyroid (for example, Armour Thyroid)

What To Think About

It is not clear how well thyroid-stimulating hormone (TSH) suppression therapy works on noncancerous thyroid nodules. If you have a noncancerous nodule, talk to your doctor about whether TSH suppression therapy is right for you.

TSH suppression therapy can increase your risk of heart and bone problems, especially if you have heart disease or osteoporosis. If you have heart disease, this kind of medicine can make chest pain or problems with your heart rhythm worse. It can also increase your chances of heart attack. If you have osteoporosis, TSH suppression therapy can further weaken your bones.

TSH suppression therapy-even in low doses-often causes hyperthyroidism, especially if you have many thyroid nodules (multinodular goiter). Your doctor will regularly check to see how well your thyroid gland is working and adjust how much medicine you are taking in order to prevent hyperthyroidism.

If a nodule is noncancerous but is producing too much thyroid hormone, causing hyperthyroidism, antithyroid medicines may be used before radioactive iodine treatment. For more information on treating hyperthyroidism, see the topic Hyperthyroidism.

Surgery

Surgery is the best treatment for thyroid nodules that are:

• Cancerous (malignant).
• Suspected to be cancerous.
• Noncancerous (benign) but large enough to cause problems with breathing or swallowing.

People who develop thyroid nodules after receiving radiation treatment to the head, neck, or chest are more likely to need surgery because their risk for developing thyroid cancer is greater. But most nodules in people who have had radiation therapy are not cancerous.

For information about thyroid cancer and its treatment, see the topic Thyroid Cancer.

Surgery Choices

The most common surgical procedure to remove thyroid nodules is thyroidectomy.

What To Think About

Most thyroid cancers grow and spread so slowly that you can delay surgery for a short time if you have a suspicious nodule that is not causing problems. If you choose to postpone surgery, your nodule should be watched closely by an endocrinologist.

Other Treatment

Other treatment for thyroid nodules includes fine-needle aspiration and radioactive iodine.

During a fine-needle aspiration, an endocrinologist uses a small needle to drain a fluid-filled (cystic) nodule. Some cysts do not return after they are drained. But most cysts do come back. If your nodule comes back after being drained once or twice, surgery to remove it is usually recommended.

Radioactive iodine is sometimes used to treat hyperthyroidism in people who have noncancerous thyroid nodules.

Other Treatment Choices

Fine-needle aspiration to drain cystic nodules

Radioactive iodine therapy

What To Think About

Surgical removal is recommended for cystic nodules that come back, especially those larger than 1.6 in. (4.1 cm) in diameter.

Hypothyroidism (too little thyroid hormone) occurs in about 10 out of 100 people within 5 years after being treated with radioactive iodine for thyroid nodules.¹ For this reason, your doctor will check your thyroid hormone levels regularly after you have this treatment.

If a thyroid nodule is not cancerous but is making too much thyroid hormone, causing hyperthyroidism, antithyroid medicines may be used before radioactive iodine treatment. For more information on treating hyperthyroidism, see the topic Hyperthyroidism.

Other Places To Get Help

Organizations

References

Citations

1. Hegedüs L (2004). The thyroid nodule. New England Journal of Medicine, 351(17): 1764-1771.

2. Welker MJ, Orlov D (2003). Thyroid nodules. American Family Physician, 67(3): 559-566.

Other Works Consulted

• American Thyroid Association Guidelines Taskforce (2006). Management guidelines for patients with thyroid nodules and differentiated thyroid cancer. Thyroid, 16(2): 1-33. Also available online: http://www.liebertpub.com/thy.

• Carling T, Udelsman R (2005). Thyroid tumors. In VT Devita Jr et al., eds., Cancer: Principles and Practice of Oncology, 7th ed., vol. 2, pp. 1502-1520. Philadelphia: Lippincott Williams and Wilkins.

• Jameson JL, Weetman AP (2008). Hypothyroidism section of Disorders of the thyroid gland. In AS Fauci et al., eds., Harrison's Principles of Internal Medicine, 17th ed., vol. 2, pp. 2229-2233. New York: McGraw-Hill.

• Ladenson PW (2005). Thyroid. In DC Dale, DD Federman, eds., ACP Medicine, section 3, chap. 1. New York: WebMD.

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