Hyperthyroidism

Background

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

Causes

1. Primary Hyperthyroidism
   1. Graves disease (toxic diffuse goiter)
      1. Most common cause (85% of cases)
      2. Associated with diffuse goiter, ophthalmopathy, local dermopathy
   2. Toxic multinodular goiter
      1. 2nd most common cause
   3. Toxic nodular (adenoma) goiter
      1. Enlarged thyroid gland w/ small nodules that overproduce thyroid hormone
2. Secondary Hyperthyroidism
   1. Thyrotropin-secreting pituitary adenoma
   2. Thyroiditis
   3. Hashimoto thyroiditis
      1. Initially gland is overactive (hyperthyroidism state) followed by hypothyroidism
   4. Subacute painful thyroiditis (de Quervain thyroiditis)
   5. Subacute painless thyroiditis
   6. Radiation thyroiditis
3. Other causes
   1. Metastatic thyroid cancer
   2. Iodine-induced thyrotoxicosis
   3. Amiodarone (contains iodine)

Clinical Features

1. Constitutional
   1. Lethargy
   2. Diaphoresis
   3. Weakness
   4. Fever
   5. Heat intolerance
   6. Weight loss
2. Neuropsychiatric
   1. Emotional lability
   2. Fine tremor
   3. Anxiety
   4. Muscle wasting
   5. Confusion
   6. Hyperreflexia
   7. Coma
   8. Periodic paralysis
   9. Psychosis
3. Ophthalmologic
   1. Diplopia
   2. Lid lag
   3. Eye irritation
   4. Exophthalmos
   5. Ophthalmoplegia
4. Endocrine
   1. Neck fullness/tenderness (thyroid gland)
5. Cardiorespiratory
   1. Dyspnea
   2. Widened pulse pressure
   3. Palpitations
   4. Systolic hypertension
   5. Chest pain
   6. Sinus tachycardia
   7. A-fib/flutter
   8. CHF
6. GI
   1. Diarrhea
   2. Hyperactive bowel sounds
7. Reproductive
   1. Oligomenorrhea
   2. Gynecomastia
   3. Telangiectasia
8. Gynecologic
   1. Menorrhagia
   2. Sparse pubic hair
9. Hematologic
   1. Anemia
   2. Leukocytosis
10. Dermatologic
    1. Hair loss
    2. Pretibial myxedema
    3. Warm, moist skin
    4. Palmar erythema
    5. Onycholysis

See Also

• Thyroid Storm
• Thyroid (General)

Source

Tintinalli