Thyroid nodules
Thyroid nodules are solid or fluid-filled lumps that form within your thyroid. Most thyroid nodules aren’t serious and don’t cause symptoms. Only a small percentage of thyroid nodules are cancerous. Some nodules are easy to feel, but others may be deep in the thyroid tissue or low in the gland, making them hard to find or detect. In fact, only 4 to 7 percent of thyroid nodules are palpable. Thyroid nodules are classified as cold, warm, or hot, depending on whether they produce thyroid hormones or not: Cold nodules don’t produce thyroid hormones. Warm nodules act as normal thyroid cells. Hot nodules overproduce thyroid hormones.
Symptoms
Often, a thyroid nodule has no signs or symptoms. When there are symptoms, these may depend on where the nodule is. Although rare, nodules can press against other structures in the neck and cause symptoms, including:
- a hoarse voice
- a tickling feeling in the throat
- breathing difficulties
- problems with swallowing
- choking sensation when lying flat
- swollen lymph nodes
- Rarely, a person may have pain at the site of the nodule that travels to the ear or jaw.
If your thyroid nodule is producing excess thyroid hormones, you may develop symptoms of hyperthyroidism, such as:
- rapid, irregular heartbeat
- unexplained weight loss
- muscle weakness
- difficulty sleeping
- nervousness
- Heat sensitivity (trouble dealing with heat)
Thyroid nodules may also be associated with low thyroid hormone levels, or hypothyroidism. Symptoms of hypothyroidism include:
- persistent fatigue
- unexplained weight gain
- constipation
- sensitivity to cold
- dry skin and hair
- brittle nails
- Frequent, heavy menstrual periods
- Depression
- Generalized edema (swelling)
Causes
Several conditions can cause nodules to develop in your thyroid gland, including:
Overgrowth of normal thyroid tissue: An overgrowth of normal thyroid tissue is sometimes referred to as a thyroid adenoma. It’s unclear why this occurs, but it’s not cancerous and isn’t considered serious unless it causes bothersome symptoms from its size. Some thyroid adenomas lead to hyperthyroidism.
Thyroid cyst: Fluid-filled cavities (cysts) in the thyroid degenerating thyroid.Often, solid components are mixed with fluid in thyroid cysts.
Chronic inflammation of the thyroid: Hashimoto’s disease, a thyroid disorder, can cause thyroid inflammation and result in enlarged nodules. This often is associated with hypothyroidism.
Multinodular goiter: The term goiter is used to describe any enlargement of the thyroid gland, which can be caused by iodine deficiency or a thyroid disorder. A multinodular goiter contains multiple distinct nodules within the goiter, but its cause is less clear.
Thyroid cancer: The chances that a nodule is cancerous are small. However, a nodule that is large and hard or causes pain or discomfort is more worrisome. You will likely want to have it checked by your doctor. Certain factors increase your risk of thyroid cancer, such as a
- family history of thyroid
- or other endocrine cancers
- having a history of radiation exposure from medical therapy or from nuclear fallout.
Iodine deficiency: Lack of iodine in your diet can sometimes cause your thyroid gland to develop thyroid nodules. But iodine deficiency is uncommon in the United States, where iodine is routinely added to table salt and other foods.
How is a thyroid nodule diagnosed?
You may not know you have a nodule until your doctor finds it during a general physical exam. They may be able to feel the nodule. If they suspect you have a thyroid nodule, they will probably refer you to an endocrinologist. This type of doctor specializes in all aspects of the endocrine (hormone) system, including the thyroid. Your endocrinologist will want to learn if you: underwent radiation treatment on your head or neck as an infant or child have a family history of thyroid nodules have a history of other thyroid problems .They will use one or more of the following tests to diagnose and assess your nodule:
- thyroid ultrasound, to examine the structure of the nodule
- thyroid scan, to learn if the nodule is hot, warm, or cold (this test is typically performed when the thyroid is overactive)
- fine needle aspiration, to collect a sample of the nodule for testing in a laboratory
- blood tests, to check your levels of thyroid hormones and thyroid stimulating hormone (TSH)
Treatment
Treatment for thyroid nodules will depend on their cause.
Pharmacotherapy: If a nodule is benign, the doctor will continue to monitor the person closely with physical exams and an ultrasound every few months. If the nodule is producing hormones, the individual may need medication to regulate these hormone secretions.
Surgery: If the doctor suspects cancer, they may recommend surgery to remove the cancerous tissue. They may also suggest surgery if any of the following occur:
- the nodule is large or growing rapidly
- an ultrasound scan reveals a complex cyst
- there are signs of compression of the windpipe or food pipe
References
https://www.mayoclinic.org/diseases-conditions/thyroid-nodules/symptoms-causes/syc-20355262
https://www.healthline.com/health/thyroid-nodule#prevention
https://my.clevelandclinic.org/health/diseases/13121-thyroid-nodule
