Hyperthyroidism

Background

  • Hyperthyroidism: Excess circulating hormone resulting from thyroid gland hyperfunction
  • Thyrotoxicosis: Excess circulating thyroid hormone originating from any cause

Causes

Primary Hyperthyroidism

  • Graves disease (toxic diffuse goiter)
    • Most common cause (85% of cases)
    • Associated with diffuse goiter, ophthalmopathy, local dermopathy
  • Toxic multinodular goiter
    • 2nd most common cause
  • Toxic nodular (adenoma) goiter
    • Enlarged thyroid gland with small nodules that overproduce thyroid hormone

Secondary Hyperthyroidism

  • Thyrotropin-secreting pituitary adenoma
  • Thyroiditis
  • Hashimoto thyroiditis
    • Initially gland is overactive (hyperthyroidism state) followed by hypothyroidism
  • Subacute painful thyroiditis (de Quervain thyroiditis)
  • Subacute painless thyroiditis
  • Radiation thyroiditis

Other causes:

Clinical Features

Constitutional signs:

  • Lethargy
  • Diaphoresis
  • Weakness
  • Fever
  • Heat intolerance
  • Weight loss

Neuropsychiatric:

  • Emotional lability
  • Fine tremor
  • Anxiety
  • Muscle wasting
  • Confusion
  • Hyperreflexia
  • Coma
  • Periodic paralysis
  • Psychosis

Ophthalmologic:

  • Diplopia
  • Lid lag
  • Eye irritation
  • Exophthalmos
  • Ophthalmoplegia

Endocrine:

  • Neck fullness/tenderness (thyroid gland)

Cardiorespiratory:

GI:

Reproductive:

  • Oligomenorrhea
  • Gynecomastia
  • Telangiectasia

Gynecologic:

  • Menorrhagia
  • Sparse pubic hair

Hematologic:

  • Anemia
  • Leukocytosis

Dermatologic:

  • Hair loss
  • Pretibial myxedema
  • Warm, moist skin
  • Palmar erythema
  • Onycholysis

Apathetic hyperthyroidism: (elderly patients)[1]

  • Placid apaethetic facies
  • Depression
  • Lethargy
  • Muscular weakness and wasting
  • Excessive weight loss
  • Cardiac dysrrhythmias
  • Absent or small goiter
  • Absence of ocular symptoms
  • Agitation and confusion

Differential Diagnosis (Tachycardia)

Evaluation

Workup

  • TSH (↓)
  • Free T4 (↑)
  • Free T3 (↑)

Management

  • If asymptomatic or mild symptoms, no treatment required in ED
  • If symptomatic, consider Thyroid storm

Disposition

  • If asymptomatic or no thyroid storm, discharge with outpatient follow-up.
  • Admit for significant symptoms or thyroid storm.

See Also

References

  1. Rehman SU et al. Thyroid Disorders in Elderly Patients. South Med J. 2005;98(5):543-549.