What are thyroid nodules?

Most of the time, these little lumps aren’t anything to worry about—except in these cases

By Brianna Graham, MPH | Jan. 19, 2022 Medically reviewed by Anis Rehman, MD

Types of thyroid nodules | Causes | Symptoms | When to worry | Treatments

Your thyroid gland hugs your trachea on the front of the neck, just above your sternum. It’s usually described as a butterfly or bow tie shape. If your thyroid is in good condition, you most likely weren’t aware it was there. However, there are several conditions and diseases that can change the way it looks and feels, making it more obvious and noticeable. A thyroid nodule is one of the most common culprits.

Millions of Americans experience thyroid nodules every single year. A thyroid nodule is an abnormal lump that has grown on your thyroid gland. Some thyroid nodules are solid tissue, while others are fluid filled. Depending on the cause, you may need surgery or medication to treat it.

“Most thyroid nodules don’t need any treatment or cause any symptoms,” according to John Abikhaled, MD, general surgeon at Austin Surgeons. “However, a small percentage do, including the [approximately] 5% that are cancerous.” Here’s everything you need to know about thyroid nodules, what causes them, and how they’re treated.

Types of thyroid nodules

There are lots of different types of thyroid nodules. Over 90% of them are benign, meaning that they aren’t caused by cancer. Benign nodules can still be an indicator that something is going on. Sometimes, it’s the main symptom for an underlying illness or thyroid disorder. Depending on the kind of thyroid nodule you have, your healthcare provider will inform you of next steps.

Benign thyroid nodules

Learning that your thyroid nodule is benign, or noncancerous, can bring you great relief. But, you may still need treatment to prevent it from affecting your health. These are the most common kinds of benign thyroid nodules:

Thyroid adenoma

A thyroid adenoma is a benign tumor that has grown on your thyroid. Even though the word tumor may sound alarm bells in your mind, you can rest assured that this kind isn’t cancerous.

There are two different kinds of thyroid adenomas: inactive and active (also called toxic). If a thyroid adenoma is active, that means it can produce thyroid hormones on its own, and often too much thyroid hormone than what you need. It can result in an overactive thyroid, called hyperthyroidism, and other health issues. On the other hand, inactive thyroid adenomas don’t increase the thyroid hormones in your body.

Thyroid cyst

A cyst is a lump that is mostly filled with fluid. Some also contain bits of tissue. Thyroid cysts are usually caused by a thyroid adenoma that is breaking down. They are benign in most cases, but can contain cancerous tissues in rare instances. Thyroid cysts need to be treated with fine needle aspiration therapy, otherwise they don’t usually go away.

Goiter

Goiter is a condition that makes your thyroid gland swell, and it’s the most common thyroid condition among Americans. Some people may experience swelling across their entire thyroid gland, but other cases result in multinodular goiter. People who have multinodular goiter have several nodules spread across their thyroid. In both cases, the thyroid is usually visibly or palpably enlarged.

Malignant thyroid nodules

If a thyroid nodule is malignant, that means it’s cancerous. Thyroid cancer isn’t very common; it affects just 15.5 out of every 100,000 people in the United States. There are four main types of thyroid cancer: papillary, follicular, medullary, and anaplastic. Each type of cancer can cause a thyroid nodule, but they also have different treatment protocols and survival rates.

Papillary thyroid cancer is the most common kind of thyroid cancer. It’s caused by follicular cells in the thyroid gland and can easily spread to your lymph nodes.

Follicular thyroid cancer is also caused by follicular cells. Unlike papillary thyroid cancer, follicular thyroid cancer cells don’t usually spread to your lymph nodes. Instead, it has a higher capacity to travel to organs that are a distance away, like your lungs or bones.

Medullary thyroid cancer is also formed by follicular cells, but 1 in 4 cases is the result of genetics, according to the American Thyroid Association. Families can pass thyroid cancer down through their bloodline. Due to its ability to occur in multiple members of the same family, it’s extremely important to determine if it’s caused by genetics after you’re diagnosed. It can help detect early stage cancers in your family members and save their lives.

When they’re caught early, papillary, follicular, and medullary thyroid cancers are very treatable, with almost 100% of people surviving at least five years when it’s caught early. Anaplastic thyroid cancer is a different story, though.

Anaplastic thyroid cancer is a rare but much more aggressive than the other kinds of thyroid cancer. It grows faster and has a much lower five year survival rate than the other thyroid cancers. In fact, just 31% of people diagnosed with anaplastic thyroid cancer survive for five years or longer when it’s detected early. That number drops significantly with more advanced stages of cancer. Only 10% of people with anaplastic thyroid cancer that has spread to the lymph nodes will survive at least five years, and that number drops even lower to just 3% if it spreads even further. Luckily, this deadly cancer accounts for less than 2% of all thyroid cancer diagnoses.

Causes

There are a variety of factors that can influence the development of thyroid nodules. “Overgrowth of thyroid tissue, chronic inflammation, iodine deficiency, or other risk factors can cause thyroid nodules,” Dr. Abikhaled says. The prevalence of thyroid nodules is significantly higher in people with iodine deficiency. People with Hashimoto’s disease are also at increased risk for thyroid nodules. Smoking cigarettes and exposure to nuclear radiation also increases risk for thyroid nodule and cancer.

Despite these associations between thyroid nodules and potential causes, most cases of thyroid nodules have unknown causes. Some healthcare providers hypothesize a link between stress and thyroid issues, but there’s no proven connection as of yet.

Symptoms

There are several clues that indicate the presence of a thyroid nodule. Some people may experience multiple symptoms, while others may have none at all. If you think you might have a thyroid nodule, here’s what you should look out for:

Difficulty swallowing or breathing
Visible or palpable swelling in your neck
Fatigue
Pain in your neck or jaw
Anxiety
Weight changes (unexplained weight loss or gain)
Fast heartbeat
Irregular heartbeat
Hoarseness
Changes in your voice

Most of these symptoms are annoying, but don’t have a major impact on your quality of life. “In some cases, large nodules can result in neck deformities, discomfort, or even obstructions to breathing or swallowing,” Dr. Abikhaled says. No matter the cause, you should seek immediate medical attention if you have difficulty breathing or swallowing. Left untreated, these symptoms can lead to devastating consequences to your health.

When to worry about thyroid nodules

Due to the risk of cancer and other health conditions, your doctor will need to evaluate you if you suspect a thyroid nodule. “It is very important that patients with thyroid nodules see a physician with expertise in thyroid diseases,” reminds Dr. Abikhaled. “That way, an appropriate evaluation of the nodules can be undertaken.”

There are many ways your healthcare provider can diagnose a thyroid nodule. If you tell your doctor that you’re experiencing pain or discomfort, or that you feel a lump on your neck, they will give you a physical exam to palpate your thyroid.

Other times, your physician may suspect a thyroid issue based on weight changes or abnormal blood test results. In either case, there are a variety of tests your doctor can order to confirm your diagnosis and ascertain the cause. You may need a thyroid stimulating hormone (TSH) test to measure your thyroid function, a thyroid ultrasound, or fine needle aspiration biopsy.

If you’re worried that you might have a thyroid nodule, you most likely don’t need to worry. “A small percentage of thyroid nodules are cancerous,” explained Dr. Abikhaled.” Your doctor can order a biopsy to determine whether or not your thyroid nodule is cancerous.

Thyroid nodules treatment

Treatment options for thyroid nodules vary depending on the cause. There’s no need to treat thyroid nodules that aren’t impacting your health negatively or causing concern for cancer. However, if they’re left untreated they can cause hyperthyroidism, pain, or difficulty swallowing or breathing.

Surgery

“Your doctor may need to surgically remove part or all of your thyroid gland if it’s causing health issues,” Dr. Abikhaled says. Thyroid surgery is the most invasive treatment for thyroid nodules, but it’s not always necessary.

Medication

Benign nodules that cause hyperthyroidism can be treated with a course of radioactive iodine, which is available as an oral capsule. When taken as directed by a doctor, radioactive iodine shrinks thyroid nodules in about three months. If that doesn’t work, your doctor may prescribe a medication called methimazole to reduce the amount of thyroid hormone your body produces.

Thyroidectomy

If all else fails, surgical removal of the thyroid entirely, also called a thyroidectomy, may be necessary. This is a simple surgery where most of the young and healthy patients are discharged from the hospital after a few hours of observation. However, if you have several comorbid conditions, you may be required to stay in the hospital overnight. “People with cancerous or active thyroid nodules benefit most from this treatment, as it may cure their condition,” Dr. Abikhaled says.

After 10 days or so, you should be able to return to even your most strenuous activities, but you‘ll be dependent on medication for the rest of your life. This is because your body can’t produce thyroid hormones after your thyroid has been removed. Your doctor will prescribe a synthetic thyroid hormone replacement medication like Synthroid (levothyroxine) or Unithroid (levothyroxine). Without taking your thyroid medication, you’ll develop hypothyroidism which carries its own challenges.

If you have concerns about your thyroid, it’s always best to follow up with your primary care provider or endocrinologist. Usually, a little treatment goes a long way to prevent more complicated health issues.