Cushing's syndrome is caused by excessive levels of cortisol and can be due to either endogenous or exogenous factors. It leads to a variety of clinical manifestations and complications. Diagnosis involves testing cortisol levels through urine or blood samples. Treatment options depend on the underlying cause and may include medications to reduce cortisol levels, surgery to remove tumors, or radiotherapy. Nursing care focuses on monitoring for infections, injuries, skin breakdown, and psychological issues while providing support and education.