Hyperthyroidism is the most common hormonal disease in middle-aged to older cats; untreated disease causes significant suffering while several effective treatments can restore excellent quality of life.
The restlessness, insomnia, hypertension, and weight loss associated with uncontrolled hyperthyroidism significantly impair cat quality of life. The condition was unrecognised until the 1980s and remains underdiagnosed in some practices. Owner awareness of the condition and access to diagnostic testing, combined with effective treatment options including medical management, surgery, and radioiodine therapy, mean most cats can be successfully managed.