A 22-year-old woman presents with weight loss, heat intolerance, tremors, and palpitations. On examination, she has exophthalmos, lid lag, and a diffuse goitre. What is the most likely diagnosis? A) Graves’ disease B) Toxic multinodular goitre C) Subacute thyroiditis D) Hashimoto’s thyroiditis E) Phaeochromocytoma Correct Answer: A) Graves’ disease Explanation: Graves’ disease is the most common cause of hyperthyroidism, characterized by exophthalmos, lid lag, and a diffuse goitre. It is an autoimmune condition with TSH receptor antibodies. B) Toxic multinodular goitre → Incorrect. Causes thyrotoxicosis but no eye signs (exophthalmos). C) Subacute thyroiditis → Incorrect. Causes painful goitre and transient thyrotoxicosis. D) Hashimoto’s thyroiditis → Incorrect. Initially causes thyrotoxicosis, but progresses to hypothyroidism. E) Phaeochromocytoma → Incorrect. Causes episodic hypertension, not thyroid-related symptoms. Key Tips for PLAB 1: ✅ Graves’ disease = Thyrotoxicosis + Eye signs (exophthalmos). ✅ First-line treatment = Carbimazole or propylthiouracil. ✅ Definitive treatment = Radioactive iodine or surgery.
