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What are thyroid nodules?
Thyroid nodules are growths or lumps in the thyroid 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.footnote 1 Many don't even need treatment.
Sometimes 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 doesn't work as hard as usual.
Most thyroid nodules are not cancerous. But if tests show cancer, surgery will be done to remove the nodule.
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. Thyroid nodules are more common as you age. 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.
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 get information about your thyroid gland and nodules. This is done if the level of thyroid hormone is high. Another test called an uptake scan can be done at the same time to see how well your thyroid gland is working.
- Fine-needle aspiration, which removes a small amount of material from the nodule. The material is checked for cancer cells.
- Thyroid ultrasound, to see the number and size of nodules or to locate the nodule for fine-needle aspiration.
How are they treated?
If your nodule is not cancer (benign) and is not causing problems, your doctor will watch your nodule closely for any changes. But if the nodule is large or causing problems with swallowing or breathing, you'll need surgery to remove the nodule.
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. Or your doctor may have you take medicine (antithyroid pills) to slow down the hormone production. In some cases, surgery may be done to remove an overactive thyroid nodule.
If your nodule is cancer (malignant), 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.
Experts don't 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. Thyroid nodules are more common as you age.
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.
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).
Most thyroid nodules do not cause problems and are not cancerous.footnote 2 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 make 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. 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.
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.
When should you call your doctor?
Call your doctor if you have any signs of thyroid nodules, including:
- 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 that 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 thyroid nodules, you will need regular medical checkups to make sure that your thyroid gland is working well.
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.
- Fine-needle aspiration guided by ultrasound. Material that is removed from the nodule is checked for cancer cells. This 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 show 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 with a fine-needle aspiration.
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 get information about your thyroid gland and nodules. This is done if the level of thyroid hormone is high. Another test called an uptake scan can be done at the same time to see how well your thyroid gland is working and to see if you have hyperthyroidism.
If your nodule is not cancerous, your doctor will see you regularly to monitor the size of your nodule. He or she may do other tests, such as checking your thyroid-stimulating hormone (TSH) levels or doing a thyroid ultrasound. If your nodule grows, other tests or surgery may be needed.
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. For information about thyroid cancer and its treatment, see the topic Thyroid Cancer.
If your thyroid nodule is causing problems, such as making too much thyroid hormone (hyperthyroidism), you may need to take medicine or have surgery. For more information on hyperthyroidism, see the topic Hyperthyroidism.
When you know you have a thyroid nodule, your treatment options include:
- Observation. Your doctor may choose to check your thyroid nodule every 6 to 12 months for changes in size. Many noncancerous thyroid nodules stay the same size or shrink without treatment.
- 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 so big that it makes it hard for you to breathe or swallow. Surgery may also help relieve symptoms if other treatments, such as draining a noncancerous nodule filled with fluid (cyst), have not worked. Also, if you have a thyroid nodule that is making too much thyroid hormone, surgery may help.
- Radioactive iodine . Radioactive iodine may be used to destroy thyroid tissue if:
- Your nodule 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 may 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.
If you have a thyroid nodule:
- Take any thyroid hormone medicine your doctor prescribes at the same time each day and do not miss a dose.
- Follow your doctor's advice for getting your blood checked for thyroid hormone levels.
- 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 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. Thyroid 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 fine-needle aspiration.
Thyroid nodules cannot be prevented.
Experts do not agree on whether adults who don't have symptoms should have a thyroid test. The American Thyroid Association and the American Association of Clinical Endocrinologists recommend that testing be considered for those older than age 60. footnote 3The U.S. Preventive Services Task Force makes no recommendation for or against screening for people who do not have symptoms of thyroid problems. The USPSTF states that there is not enough evidence to support screening.footnote 4
Talk to your doctor about whether testing is right for you.
Most thyroid nodules aren't cancerous.footnote 2 Many thyroid nodules don't 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.
- Follow your doctor's directions if you miss a dose.
- 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.
Radioactive iodine is sometimes used to treat hyperthyroidism in people who have noncancerous thyroid nodules.
What to think about
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 (thyroidectomy) 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.
Thyroid-stimulating hormone (TSH) suppression therapy may be given to shrink noncancerous thyroid nodules. This uses medicines such as levothyroxine (for example, Synthroid, Levoxyl, or Levothroid), liothyronine (for example, Cytomel), liotrix (Thyrolar), or desiccated thyroid (for example, Armour Thyroid).
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.
What to think about
Hypothyroidism (too little thyroid hormone) occurs in some people after being treated with radioactive iodine for thyroid nodules. 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.
- Yassa L, et al. (2007). Long-term assessment of a multidisciplinary approach to thyroid nodule diagnostic evaluation. Cancer, 111(6): 508–516. DOI: 10.1002/cncr.23116. Accessed August 25, 2016.
- Yassa L, et al. (2007). Long-term assessment of a multidisciplinary approach to thyroid nodule diagnostic evaluation. Cancer, 111(6): 508-516. DOI: 10.1002/cncr.23116. Accessed August 25, 2016.
- Garber JR, et al; American Association of Clinical Endocrinologists and American Thyroid Association Taskforce on Hypothyroidism in Adults (2012). Clinical practice guidelines for hypothyroidism in adults: Cosponsored by the American Association of Clinical Endocrinologists and the American Thyroid Association. Endocrinology Practice, 18(6): 988–1028.
- LeFevre ML (2015). Screening for thyroid dysfunction: U.S. Preventive Services Task Force recommendation statement. Annals of Internal Medicine, published online Mar 24, 2015. DOI: 10.7326/M15-0483. Accessed April 10, 2015.
Current as of: March 31, 2020
Author: Healthwise Staff
E. Gregory Thompson MD - Internal Medicine
Kathleen Romito MD - Family Medicine
Adam Husney MD - Family Medicine
Current as of: March 31, 2020
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