thyroid nodules are solid or fluid-filled lumps that form within the thyroid, a small gland located at the base of the neck above the breastbone.

The majority of thyroid nodules aren't serious and don't cause symptoms. Some, however, may become large enough to be visible or make it difficult to swallow or breathe. Only a small percentage of thyroid nodules accounts for thyroid cancer.


Most thyroid nodules don't cause any symptoms. Occasionally, however, some nodules become so large that they can be felt, seen, often as a swelling at the base of the neck and press on the windpipe or esophagus, causing shortness of breath or difficulty swallowing.

Thyroid nodules produce additional thyroxine, a hormone secreted by the thyroid gland.  The extra thyroxine can cause symptoms of hyperthyroidism such as unexplained weight loss, intolerance to heat, tremor, nervousness and rapid or irregular heartbeat

A few thyroid nodules are cancerous (malignant), but it is difficult to tell which nodules are malignant by symptoms alone. Although the size is not a predictor of whether a nodule is malignant or not, cancerous thyroid tumors are more likely to be large fixed masses that grow quickly.


These are the conditions that can cause nodules to develop in the thyroid gland:

  • Iodine deficiency.Thyroid cyst.
  • Overgrowth of normal thyroid tissue.
  • Chronic inflammation of the thyroid (thyroiditis).
  • Multinodular goiter.
  • Thyroid cancer.

Risk Factors

Factors that may increase the risk of thyroid nodules include:

  • Exposure to high levels of radiation
  • Female sex.
  • Inherited genetic syndromes.


Complications associated with thyroid nodules include:

  • Problems swallowing or breathing.
  • Hyperthyroidism.
  • Problems associated with thyroid cancer.


Just like thyroid cancer itself, thyroid nodules cannot currently be prevented.