What are the symptoms of hyperthyroidism?

Symptoms of Hyperthyroidism

The symptoms of hyperthyroidism include tremors, nervousness, insomnia, excessive sweating, heat intolerance, tachycardia, hypertension, goiter, weight loss, palpitations, and hyperactivity. 1

Common Clinical Manifestations

Hyperthyroidism presents with a constellation of symptoms affecting multiple body systems:

Cardiovascular Symptoms

• Tachycardia and palpitations
• Hypertension (often with widened pulse pressure)
• Atrial fibrillation (especially in older patients)
• High-output heart failure in severe cases 1, 2

Neuropsychiatric Symptoms

• Anxiety and nervousness
• Insomnia
• Fine tremor of outstretched hands
• Hyperactivity 2, 1

Metabolic and Constitutional Symptoms

• Unintentional weight loss (despite increased appetite)
• Heat intolerance
• Excessive sweating
• Fatigue and muscle weakness (particularly proximal muscles) 1, 3

Gastrointestinal Symptoms

• Diarrhea or increased bowel movements
• Increased appetite 3

Dermatologic Manifestations

• Warm, moist skin
• Hair loss
• Pretibial myxedema (specifically in Graves' disease) 1

Ophthalmologic Signs (particularly in Graves' disease)

• Eyelid lag or retraction
• Exophthalmos (bulging eyes)
• Stare 1

Physical Examination Findings

During physical examination, clinicians should look for:

• Goiter (diffusely enlarged thyroid gland)
• Fine tremor of outstretched hands
• Tachycardia
• Warm, moist skin
• Lid lag and stare
• Proximal muscle weakness 1

Special Considerations

• In older adults, symptoms may be more subtle and limited to cardiovascular manifestations ("apathetic hyperthyroidism") 2
• Untreated hyperthyroidism can lead to serious complications including cardiac arrhythmias, heart failure, osteoporosis, and in rare cases, thyroid storm (a medical emergency) 1, 3
• Beta-blockers like propranolol can mask certain clinical signs of hyperthyroidism, and abrupt withdrawal may precipitate thyroid storm 4

Diagnostic Confirmation

While symptoms are important for clinical suspicion, diagnosis is confirmed by laboratory testing showing:

• Low or undetectable TSH
• Elevated free T4 and/or T3 levels 2, 1

Subclinical hyperthyroidism presents with low TSH but normal T4 and T3 levels, and may have milder or absent symptoms 2, 1.