Hyperthyroidism is the opposite of hypothyroidism: the thyroid produces too much T3 and T4, speeding up virtually every body system. The most common cause in adults is Graves’ disease, an autoimmune condition in which antibodies stimulate the thyroid continuously. Other causes include toxic multinodular goitre and thyroid nodules.
Symptoms reflect a body running too fast: weight loss despite good appetite, rapid or irregular heartbeat (palpitations), tremor, heat intolerance and excessive sweating, anxiety and irritability, loose stools, and fatigue. In Graves’ disease, eye involvement (exophthalmos) is a distinctive feature.
Nutritional implications: the hypermetabolic state dramatically increases energy and protein needs. Involuntary weight loss and muscle wasting are common before treatment. Ensuring adequate calorie and protein intake helps limit muscle loss. Bone density is also affected by prolonged hyperthyroidism — calcium and vitamin D adequacy matters.
Iodine intake warrants careful attention: since iodine is the raw material for thyroid hormones, high-dose iodine supplements (kelp, seaweed supplements, certain contrast agents) can worsen or trigger hyperthyroidism in susceptible individuals.
Treatment is medical: antithyroid drugs (carbimazole, propylthiouracil), radioactive iodine therapy, or surgery. Nutrition supports treatment but does not replace it. Work with your endocrinologist and a registered dietitian.