If you’ve noticed changes like a fast heartbeat, sudden weight loss or a lump in your neck, you might be dealing with more than everyday stress. These could be signs of a toxic thyroid nodule. It is a lump in your thyroid that produces hormones, even when your body doesn’t need them.
This nodule can lead to serious health problems, but there are effective treatments that can help you feel like yourself again.
We spoke with Banner - University Medicine’s Mira Milas, MD, chief of endocrine surgery, and Christian Nasr, MD, chief of endocrinology, to learn more about this condition and the treatment options available.
What is a toxic thyroid nodule?
A toxic thyroid nodule – also called a toxic adenoma or autonomously functioning thyroid nodule – is a lump in your thyroid gland that makes thyroid hormone on its own. Normally, your thyroid is controlled by a hormone called thyroid stimulating hormone (TSH) from the pituitary gland. But toxic nodules don’t follow these rules. They make extra hormones, even when your body doesn’t need them.
“Unlike most thyroid nodules, which are inactive, toxic nodules actually produce thyroid hormones like T3 and T4 independently,” Dr. Nasr said.
These hormones control your metabolism, energy levels and many body functions. So when there’s too much of them in your system, it can throw your body out of balance.
“Toxic nodules are different from other causes of hyperthyroidism (where the whole gland is overactive), such as in Graves’ disease,” Dr. Nasr said. “With a toxic thyroid nodule, only the nodule is overworking.”
What causes a toxic thyroid nodule?
Your thyroid is a butterfly-shaped gland in your neck that helps regulate your body’s metabolism. A toxic nodule happens when part of the gland grows a lump that starts making its own hormones.
“These nodules are usually caused by unchecked growth of the thyroid cells and they usually originate from a single abnormal cell,” Dr. Nasr said.
In some people, there will be a single nodule. In others, multiple nodules can become overactive. The condition tends to develop slowly over time and is more common in older adults.
Toxic thyroid nodule symptoms
Toxic nodules cause symptoms in two main ways: by pressing on nearby structures or by producing too much hormone.
Local symptoms might include:
- A lump you can see or feel in your neck
- Pressure or discomfort in the front of the neck
- Problems swallowing
Hormone-related symptoms might include:
- A fast or irregular heartbeat (arrhythmia)
- Unintentional weight loss
- Feeling nervous, anxious or shaky
- Trouble sleeping
- Heat intolerance or excessive sweating
- More frequent bowel movements
If you are experiencing symptoms of a thyroid problem, talk to your health care provider or a Banner Health specialist.
How are toxic thyroid nodules diagnosed?
If your health care provider suspects you have a thyroid problem, the first step is usually a blood test to check your TSH level. Low TSH may mean your thyroid is overactive.
“If TSH is low, we check T3 and T4 hormone levels next,” Dr. Nasr said. “If those are high, it’s considered overt hyperthyroidism. If they’re normal, it may be subclinical hyperthyroidism.”
To confirm the cause, you may have:
- A thyroid uptake and scan to see if the nodule absorbs more or less radioactive material than the rest of the thyroid
- A thyroid ultrasound to see the size and appearance of the nodule
On a scan, a toxic nodule usually appears as a “hot nodule.” It lights up brightly because it’s taking in more iodine and making more hormone than the rest of the gland.
If you are diagnosed with a toxic thyroid nodule, your provider may refer you to an endocrinologist and/or endocrine surgeon.
Treatment options for a toxic thyroid nodule
If you have a toxic thyroid nodule, your provider will help you decide the best treatment based on your symptoms, age, health and personal preference.
1. Observation (watchful waiting)
Sometimes, it’s safe to monitor the nodule with regular checkups and lab tests. This is helpful if your symptoms are mild or hormone levels are only slightly high.
2. Medication
Anti-thyroid drugs like methimazole or propylthiouracil (PTU) may help block hormone production. Beta blockers like propranolol can help with symptoms like a fast heartbeat or shakiness.
“Medications can be helpful but some people don’t tolerate them well,” Dr. Milas said. “Side effects can include abnormal liver blood tests or low white blood cell counts, which can increase your risk for infection.”
Medications may be used short-term to prepare for other treatments or as a long-term option if surgery or other procedures aren’t possible.
3. Radioactive iodine (RAI)
The word “radioactive” can sound alarming, but RAI uses a very small, safe dose of radiation. It’s been used for decades to treat overactive thyroid problems.
You take RAI as a pill. Because your thyroid naturally absorbs iodine, the treatment goes straight to the nodule. It slowly damages the overactive tissue, stopping the production of too many hormones.
“It can take weeks or months to work and some people may need a second dose,” Dr. Milas said. “But RAI is a good choice if you want to avoid surgery and your nodule shows overactivity.”
4. Radiofrequency ablation (RFA)
RFA is a minimally invasive treatment that uses heat to destroy the nodule. It’s done with a special needle guided by ultrasound, right in the clinic.
“RFA is done with local anesthesia and you go home the same day,” Dr. Milas said.
RFA may be a good option if you can’t have surgery or prefer a non-surgical approach. But it has its limitations.
“Up to 71% of people may need a second treatment,” Dr. Milas said. “In some cases, the nodule may regrow.”
5. Surgery
Surgery is often the best long-term solution, especially if the nodule is:
- 4 cm or larger
- Causing pressure or visible swelling
- Possibly cancerous
- Not responding to other treatments
- Causing serious hormone symptoms
“If the nodule is the only active part of the thyroid gland, we can remove just that side of the gland,” Dr. Milas said. “Most people don’t need lifelong medication after that.”
Surgery is outpatient and done through a small, cosmetic incision (cut). Risks are low and recovery is usually quick.
When to consider treating a toxic thyroid nodule
You should think about treatment if:
- Your symptoms are affecting your daily life
- The nodule is large or pressing on your throat
- Your heart rhythm is irregular or too fast
- You have osteoporosis or bone loss
- You’re worried about cancer risk
- You prefer a solution instead of ongoing medication
“Uncontrolled hyperthyroidism can lead to serious problems like atrial fibrillation, blood clots or osteoporosis,” Dr. Milas said. “This isn’t something to ignore.”
Even if you don’t have strong symptoms now, the condition usually doesn’t get better on its own. Talk to your health care provider about treatment options.
Takeaway
If you’ve been diagnosed with a toxic thyroid nodule – or think you might have one – don’t wait to get care. At Banner Health, you’ll find a team of experts specializing in thyroid care, from diagnosis to advanced treatments like RFA and surgery.
Schedule an appointment with a Banner Health thyroid specialist or learn more about your treatment options.
