A thyroid nodule is a growth (lump) in the thyroid gland. The thyroid gland is located at the front of the neck, just above where your collarbones meet in the middle.
Thyroid nodules are growths of cells in the thyroid gland.
These growths can be:
- Not cancer (benign) or thyroid cancer (malignant)
- Fluid-filled (cysts)
- One nodule or a group of small nodules
- Producing thyroid hormones (hot nodule) or not making thyroid hormones (cold nodule)
Thyroid nodules are more common in women than in men. A person's chance of getting a thyroid nodule increases with age.
Only a few thyroid nodules are due to thyroid cancer.
A thyroid nodule is more likely to be cancer if you:
- Have a hard nodule
- Have a nodule that is stuck to nearby structures
- Have a family history of thyroid cancer
- Have noticed a change in your voice
- Are younger than 20 or older than 70
- Have a history of radiation exposure to the head or neck
- Are male
Causes of thyroid nodules are not always found, but can include:
- Hashimoto's disease
- Lack of iodine in the diet
Most thyroid nodules do not cause symptoms.
Large nodules can press against other structures in the neck. This can cause symptoms such as:
- A visible goiter (enlarged thyroid gland)
- Hoarseness or changing voice
- Pain in the neck
- Problems breathing, especially when lying down flat
- Problems swallowing food
Nodules that produce thyroid hormones will likely cause symptoms of overactive thyroid gland, including:
- Warm, sweaty skin
- Fast pulse
- Increased appetite
- Skin blushing or flushing
- Weight loss
- Irregular menstrual periods
Older people with a nodule that produces too much thyroid hormone may have only vague symptoms, including:
- Chest pain
- Memory loss
Thyroid nodules are sometimes found in people who have Hashimoto's disease.
This may cause symptoms of an underactive thyroid gland, such as:
- Dry skin
- Face swelling
- Hair loss
- Feeling cold when other people do not
- Weight gain
- Irregular menstrual periods
Very often, nodules produce no symptoms. Health care providers find thyroid nodules only during a routine physical exam or imaging tests that are done for another reason. A few people have thyroid nodules that are big enough that they notice the nodule on their own, and ask a provider to examine their neck.
If a provider finds a nodule or you have symptoms of a nodule, the following tests may be done:
- Thyroid blood tests
- Thyroid ultrasound
- Thyroid scan (nuclear medicine)
- Fine needle aspiration biopsy of the nodule or of multiple nodules
Your provider may recommend surgery to remove all or part of your thyroid gland if the nodule is:
- Due to thyroid cancer
- Causing symptoms such as swallowing or breathing problems
- If the fine needle biopsy is inconclusive, and your provider can't tell whether the nodule is a cancer
- Making too much thyroid hormone
People with nodules that are making too much thyroid hormone may be treated with radioiodine therapy. This reduces the size and activity of the nodule. Pregnant women are not given this treatment.
Both surgery to remove thyroid gland tissue and radioactive iodine treatment can cause lifelong hypothyroidism (underactive thyroid). This condition needs to be treated with thyroid hormone replacement.
For noncancerous nodules that do not cause symptoms and are not growing, the best treatment may be:
- Careful follow-up with a physical exam and ultrasound
- A thyroid biopsy repeated 6 to 12 months after diagnosis, especially if the nodule has grown
Another possible treatment is an ethanol (alcohol) injection into the nodule to shrink it.
Noncancerous thyroid nodules are not life-threatening. Many do not require treatment. Follow-up exams are enough.
The outlook for thyroid cancer depends on the type of cancer. For most common kinds of thyroid cancer, the outlook is very good after treatment.