**2. Epidemiology**

Graves' Disease accounts for 70–80% cases of hyperthyroidism in iodine sufficient population, where as it accounts for 50% cases of hyperthyroidism in iodine deficient areas of world [4, 5].

Annual incidence for GD is 20–50 person per 100,000 population and life time risk for developing GD is 3% for women and 0.5% for men [6, 7]. Though GD can occur any age but peak incidence is seen during adulthood in between 20 to 50 years of age [8]. GD is more common in Caucasians as compare to Asian and least common among black African [9, 10]. The annual incidence of thyroid associated orbitopathy is 16 cases per 100000 in women and 3 cases per 100000 in men and is more in smokers [11]. Pretibial myxedema is a very rare complication of GD, is seen in 1.5 cases per 100000 case of GO [12]. Studies have shown that GD with nodule formation have higher incidence of thyroid carcinoma perticularly tall Cell Variant of papillary thyroid cancer (a more aggressive form of cancer) was significantly more common [13, 14].
