Cushing syndrome is caused by prolonged exposure to high levels of corticosteroids and is characterized by specific physical manifestations. It can be caused by an adrenal or pituitary tumor or exogenous glucocorticoid administration. Diagnosis involves laboratory tests and imaging to evaluate cortisol levels and locate any tumors. Treatment depends on the cause but may include surgical removal of tumors, radiation, or medication to inhibit corticosteroid production. Nursing care focuses on monitoring for complications and managing side effects through diet, exercise and medication adherence.