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Hyperthyroidism: Symptoms and Risk Factors

Hyperthyroidism is a condition in which the thyroid gland produces too much thyroid hormone. Thyroid hormones influence a wide variety of functions in the body, including cardiac, nerve, gastrointestinal, and mental function.

The majority of cases are caused by Graves’ disease, an autoimmune disease that damages the thyroid gland, causing it to overproduce thyroid hormone. Other causes of hyperthyroidism include tumors of the thyroid or pituitary glands, inflammation of the thyroid gland, or excessive ingestion of thyroid hormone pills. The disorder may also be associated with other autoimmune diseases, including Addison’s disease and type 1 diabetes mellitus.

The most severe form of hyperthyroidism is thyroid storm, which can be caused by thyroid surgery, acute stress (e.g., infection, trauma, or nonthyroid surgery), or an overdose of iodine in a patient with existing hyperthyroidism. This condition may have symptoms of extreme fever (up to 104 F to106 F), severe nausea, vomiting, jaundice (yellowish discoloration of the skin), agitation, or delirium, and may ultimately lead to seizures and coma.


  • Fast heart rate
  • Palpitations
  • Heat intolerance
  • Weight loss
  • Menstrual irregularities
  • Nausea and vomiting
  • Restlessness
  • Anxiety
  • Tremor

Further signs and symptoms depend on the cause and severity of hyperthyroidism. For example, in Graves’ disease, typical symptoms are a goiter (an abnormal lump in the neck), drooping eyelids, and thickening and redness of the skin of the legs.

Risk Factors

Hyperthyroidism is more common in females. Also, individuals with certain genes have an increased risk for Graves’ disease.


Hyperthyroidism: Diagnosis and Treatment >>