Endocrine diseases are prevalent in cats, and the most frequent ones are diabetes and hyperthyroidism. Hyperthyroidism in cats is a common endocrine disorder typically seen in older felines, characterized by an overproduction of thyroid hormones (T3 and T4) from an enlarged, usually benign thyroid gland. This hormone surge ramps up metabolism, leading to classic symptoms like weight loss despite an increased appetite, hyperactivity, restlessness, and a poor coat condition. Other signs may include increased thirst, vomiting, and heart murmurs or hypertension due to the cardiovascular strain. If untreated, hyperthyroidism can lead to heart disease, high blood pressure, and kidney damage. Treatment options include medication, dietary management, surgery, or radioactive iodine therapy, depending on the cat’s health status and owner’s preference.