Exophthalmic goitre, commonly known as Grave's disease is a condition arising from an increase in the production of thyroxine hormone by the thyroid gland, also called hyperthyroidism.
Hyperthyroidism leads to increased metabolism, an increase in ventilation and heart rate, nervousness and irritability, and other symptoms.
Bulged out and puffy eyes (exophthalmos) is a classic sign of hyperthyroidism giving a staring face appearance to the person and hence the name Grave's disease .
Final answer: Exophthalmic goitre results due to hyperthyroidism.