Overview
Definition
Overproduction of thyroid hormones. Graves' disease is an autoimmune disorder that results in the overproduction of thyroid hormones.
Epidemiology
More common in women (approx 10:1 ratio). Peak onset between 20-40 years.
Etiology & Risk Factors
- Graves' Disease: Autoantibodies (TSI) stimulate the TSH receptor, causing unregulated hormone synthesis.
- Toxic multinodular goiter
- Toxic adenoma
- Thyroiditis (transient hyperthyroidism due to release of pre-formed hormone)
Clinical Symptoms
- Weight loss despite increased appetite
- Heat intolerance and diaphoresis
- Palpitations, tachycardia, and tremors
- Frequent bowel movements
- Graves' specific: Exophthalmos (proptosis/bulging eyes), Pretibial myxedema, Thyroid bruit
Clinical Approach
Diagnosis
- TSH: Suppressed (low/undetectable)
- Free T4 and T3: Elevated
- Antibodies: Thyroid Stimulating Immunoglobulin (TSI) and TSH-Receptor Antibodies (TRAb) are positive in Graves'
- Radioactive Iodine Uptake (RAIU): Diffusely increased uptake in Graves'
Management
- Symptom control: Beta-blockers (Propranolol blocks peripheral conversion of T4 to T3)
- Thioamides: Methimazole (preferred) or Propylthiouracil (PTU - preferred in 1st trimester of pregnancy or thyroid storm)
- Definitive: Radioactive Iodine (131-I) ablation or surgical Thyroidectomy
Complications
- Thyroid Storm (life-threatening hypermetabolic state often triggered by infection/surgery)
- Atrial Fibrillation
- Osteoporosis (due to increased bone turnover)