Graves' disease is an autoimmune thyroid disease in which the body produces IgG antibodies to the thyroid-stimulating hormone (TSH) receptor. It is the most common cause of thyrotoxicosis and is typically seen in women aged 30-50 years.

Features seen in Graves' but not in other causes of thyrotoxicosis
Autoantibodies
Thyroid scintigraphy

Thyroid scintigraphy (I-123) shows homogenous uptake consistent with Graves' disease - e Image used on license from Radiopaedia
Despite many trials, there is no clear guidance on the optimal management of Graves' disease. Treatment options include anti-thyroid drugs (ATDs, for example carbimazole), radioiodine treatment and surgery.
Anti-thyroid drugs have emerged as the most popular first-line therapy for Graves' disease in recent years. Factors that particularly support their use include anti-thyroid drugs significant symptoms of thyrotoxicosis, or patients with a significant risk of hyperthyroid complications (e.g. elderly patients, cardiovascular disease).
Initial treatment to control symptoms