What are the signs and symptoms of hyperthyroidism?

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Last updated: October 27, 2025View editorial policy

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Signs and Symptoms of Hyperthyroidism

Hyperthyroidism is characterized by tremors, nervousness, insomnia, excessive sweating, heat intolerance, tachycardia, hypertension, and goiter, which can lead to serious complications if left untreated. 1, 2

Common Systemic Symptoms

  • Cardiovascular manifestations: Tachycardia, hypertension, palpitations, decreased systemic vascular resistance, increased cardiac output, and potential pulmonary artery hypertension 1
  • Neurological symptoms: Tremors, nervousness, anxiety, hyperactivity, and insomnia 1, 2
  • Dermatological symptoms: Excessive sweating, heat intolerance, and hair loss 1, 2
  • Gastrointestinal symptoms: Diarrhea and unintentional weight loss 3

Specific Clinical Findings

  • Goiter: Diffuse enlargement of the thyroid gland, particularly common in Graves' disease 4, 3
  • Ophthalmologic signs: Eyelid lag or retraction, exophthalmos (bulging eyes), and stare, particularly in Graves' disease 4, 3
  • Dermatologic signs: Localized and pretibial myxedema (in Graves' disease) 4

Severe Manifestations

  • Thyroid storm: A rare but life-threatening emergency characterized by severe acute exacerbation of hyperthyroidism symptoms, requiring immediate medical attention 4, 2
  • Cardiac complications: Heart failure in severe, long-standing cases, particularly with persistent tachycardia or rapid atrial fibrillation 1
  • Pregnancy complications: Increased risk of severe preeclampsia, preterm delivery, heart failure, and possibly miscarriage in pregnant women 4, 2

Important Clinical Considerations

  • Symptoms can vary in intensity depending on the severity of hyperthyroidism, patient age, and duration of disease 3
  • Elderly patients may present with subtle or atypical symptoms, sometimes referred to as "apathetic hyperthyroidism," with predominant cardiovascular manifestations 3
  • Subclinical hyperthyroidism (low TSH with normal T3/T4) may present with milder symptoms or be asymptomatic 3

Diagnostic Approach

  • Diagnosis is generally based on clinical symptoms plus laboratory findings showing elevated free thyroxine (FT4) level or free thyroxine index (FTI) with suppression of thyroid-stimulating hormone (TSH) 4
  • In Graves' disease (responsible for 95% of hyperthyroidism cases in pregnancy), the presence of TSH receptor antibodies confirms the diagnosis 4, 5

Complications of Untreated Hyperthyroidism

  • Cardiac arrhythmias, particularly atrial fibrillation 2, 3
  • Osteoporosis due to accelerated bone turnover 3
  • Adverse pregnancy outcomes 2
  • Increased mortality risk 3

Remember that prompt recognition of these signs and symptoms is crucial for early diagnosis and treatment to prevent serious complications of hyperthyroidism.

References

Guideline

Hyperthyroidism Management

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Guideline

Hyperthyroidism Diagnosis and Treatment

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Research

Hyperthyroidism: A Review.

JAMA, 2023

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

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.

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