Your thyroid is a gland in your neck that makes hormones that control many bodily functions. An enlarged thyroid gland is called a goiter.

One type of goiter is a multinodular goiter, in which an enlarged thyroid will have separate bumps (nodules) on it. Most multinodular goiters don’t cause symptoms. The cause is usually unknown.

Multinodular goiters are associated with a higher risk of thyroid cancer. However, researchers don’t yet understand the connection between the two. If you do have a multinodular goiter, your doctor will most likely screen you for thyroid cancer as well.

Treatment for multinodular goiter varies depending on:

  • whether you have hyperthyroidism
  • the size of the goiter
  • whether any of the nodules are cancerous

Most multinodular goiters don’t cause any symptoms and are discovered during a routine physical exam.

If you have a toxic multinodular goiter, which makes too much thyroid hormone, you might have symptoms of hyperthyroidism. These include:

  • sudden and unexplained weight loss
  • rapid heartbeat
  • increased appetite
  • nervousness or anxiety
  • tremors, usually in your hands
  • sweating
  • increased sensitivity to heat

A multinodular goiter that grows large can also cause symptoms, especially if it starts to grow into your chest. Symptoms of a large goiter include:

  • difficulty breathing or swallowing
  • feeling like you have food stuck in your throat
  • having a “full” feeling in your neck

Very large goiters might also be visible in your neck.

In most cases, the cause of a multinodular goiter is unknown. Hashimoto’s thyroiditis is associated with a higher risk of thyroid nodules, which can lead to goiter formation. Hashimoto’s is an autoimmune disorder and the most common cause of hypothyroidism in the United States. In hypothyroidism, the thyroid doesn’t produce enough hormones.

In addition, iodine deficiency can cause multinodular goiters, but this is very rare in the United States.

Up to 20 percent of people with multinodular goiters will also develop thyroid cancer. Approximately 1.2 percent of the general population in the United States will be diagnosed with thyroid cancer at some point in their life, so multinodular goiters do increase your odds of developing this type of cancer. Learn how a “neck check” you can do at home may help detect thyroid cancer.

The cause of thyroid cancer is unknown. Researchers don’t yet understand the connection between multinodular goiters and thyroid cancer. However, because multinodular goiters are a risk factor for thyroid cancer, people with this type of goiter should be screened.

When your doctor finds a multinodular goiter, you will likely have an ultrasound of your thyroid gland. Depending on the results of the ultrasound, they might do a fine needle aspiration biopsy to see if any of the nodules are cancerous.

You should be further screened if you have any other risk factors for thyroid cancer or if nodules look suspicious on a thyroid ultrasound.

Some multinodular goiters can be toxic, which means they make too much thyroid hormone. This causes hyperthyroidism. Hyperthyroidism can be treated with medication that stops the production of thyroid hormone, radioactive iodine, or removal of thyroid gland tissue.

Very large multinodular goiters can also cause what are called compression symptoms, such as trouble breathing or swallowing. If your multinodular goiter is large enough to cause these symptoms, your doctor will most likely recommend surgery.

Your doctor will start with a physical examination to see if your whole thyroid is enlarged and how many nodules are present. They will probably also order hormone blood tests that check thyroid function to see if your thyroid gland is functioning normally.

Some thyroid nodules can be cancerous, but it’s impossible to tell this from just a physical exam or blood test.

Therefore, your doctor might order a thyroid ultrasound. An ultrasound uses sound waves to take a picture of your thyroid. This can help your doctor tell if the nodules are fluid-filled or have calcifications, see how many and where they are, and identify potentially cancerous nodules.

If any of the nodules are suspicious or you have other risk factors, your doctor might also do a fine needle aspiration biopsy. They’ll use a very thin needle to take cells from several thyroid nodules and have them sent to a laboratory to see if they are cancerous. This type of biopsy can usually be done in a doctor’s office.

Noncancerous goiters that aren’t causing any symptoms don’t always need treatment. Sometimes your doctor might suggest watching and waiting to see if the goiter gets bigger. If the goiter does grow very large or starts to otherwise cause symptoms, there are several treatment options.

One option is radioactive iodine, which is usually used to shrink goiters in cases of hyperthyroidism. It works by destroying part of your thyroid to bring levels of thyroid hormone production back to normal. Some may end up developing hypothyroidism after radioactive iodine therapy.

Methimazole (Tapazole) and propylthiouracil are medication options that are also used to treat hyperthyroidism by decreasing the amount of thyroid hormone in your body.

If the goiter has become very large or is causing any trouble with breathing or swallowing, part or all the thyroid can be removed. How much of the thyroid is removed depends on how big the goiter is, how many nodules there are, if any nodules are toxic, or if there is cancer. Surgery is also the recommended treatment if any of the nodules are cancerous.

If all of your thyroid gland is removed, you’ll need lifelong treatment with thyroid hormone replacement medication.

Most multinodular goiters don’t cause symptoms. If you have symptoms of hyperthyroidism or are having trouble breathing or swallowing, you should see a doctor.

Multinodular goiters do increase your chance of developing thyroid cancer, but they can be treated with medication, radioactive iodine, or surgery depending on the type, if necessary. While they can cause or be related to other conditions, typically multinodular goiters themselves aren’t a life-threatening condition.