What are the symptoms of hyperthyroidism?

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Last updated: February 28, 2025 • View editorial policy

From the Guidelines

Hyperthyroidism symptoms include rapid heartbeat, unintentional weight loss, increased appetite, nervousness, anxiety, irritability, tremors in the hands, excessive sweating, heat sensitivity, fatigue, muscle weakness, difficulty sleeping, thinning skin, fine or brittle hair, and changes in menstrual patterns in women. These symptoms occur because excess thyroid hormones speed up the body's metabolism, causing many organ systems to work harder than normal 1. Some patients may develop an enlarged thyroid gland (goiter) or bulging eyes (exophthalmos), particularly in Graves' disease. The severity of symptoms varies widely among individuals and depends on factors such as age, the amount of excess thyroid hormone, and how long the condition has been present. Elderly patients may present with more subtle symptoms like heart failure or atrial fibrillation, as noted in a study published in Circulation in 2016 1. If you experience these symptoms, seek medical attention promptly as untreated hyperthyroidism can lead to serious complications including heart problems, bone loss, and a potentially life-threatening condition called thyroid storm, characterized by extremely high body temperature, rapid heart rate, and altered mental status. Key symptoms to look out for include:

  • Rapid heartbeat
  • Unintentional weight loss
  • Increased appetite
  • Nervousness, anxiety, irritability
  • Tremors in the hands
  • Excessive sweating
  • Heat sensitivity
  • Fatigue, muscle weakness
  • Difficulty sleeping
  • Thinning skin, fine or brittle hair
  • Changes in menstrual patterns in women It is essential to note that the US Preventive Services Task Force recommends screening for thyroid dysfunction, as early detection and treatment can prevent longer-term morbidity and mortality from fractures, cancer, or cardiovascular disease 2.

From the Research

Symptoms of Hyperthyroidism

The symptoms of hyperthyroidism include:

  • Anxiety, insomnia, palpitations, unintentional weight loss, diarrhea, and heat intolerance 3
  • Nervousness, heat intolerance, weight loss, and fatigue 4
  • Palpitations, heat intolerance, anxiety, and weight loss despite a normal or increased appetite 5
  • Unintentional weight loss, tachycardia, and palpitations, heat intolerance, and hyperactivity 6
  • Dysphagia, orthopnea, or voice changes due to local compression of structures in the neck by the thyroid gland in patients with toxic nodules 3
  • Stare, or exophthalmos on examination in patients with Graves disease 3

Rare Complications

Rarely, hyperthyroidism can lead to:

  • Nondiabetic ketoacidosis (NDKA) 5
  • Thyroid storm, a life-threatening condition with systemic decompensation and hyperpyrexia 4, 6

Diagnosis and Treatment

Hyperthyroidism is diagnosed by:

  • Suppressed thyroid-stimulating hormone (TSH) with elevated thyroid hormone (TH) levels 3, 4, 6
  • Low serum TSH levels and elevated free T4 and/or T3 5 Treatment options include:
  • Antithyroid medications (methimazole and propylthiouracil) 3, 4, 7, 6
  • Radioactive iodine ablation of the thyroid gland 3, 4, 7, 6
  • Surgical thyroidectomy 3, 4, 7, 6

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.