Feline Hyperthyroidism is a common endocrine disorder in older cats, characterized by an overproduction of thyroid hormones. This condition often results from a benign tumor on the thyroid gland, leading to symptoms such as increased appetite, weight loss, and hyperactivity. Diagnosis typically involves blood tests to measure hormone levels, and treatment options include medication, radioactive iodine therapy, or surgery. Managing feline hyperthyroidism is essential for maintaining a cat's overall health and well-being, as untreated cases can lead to serious complications like heart disease.