Cardiac edema, also known as cardiogenic edema, is symmetrical edema in low hanging parts of the body caused by right heart failure. Cardiogenic edema is usually caused by right heart failure, which is mainly manifested by body circulation stasis and portal vein stasis. At the beginning of edema, it is mainly symmetrical depressed edema of both lower limbs, which gradually spreads upward and even causes edema of the abdominal wall, and visceral edema, ascites, pleural fluid, etc. can also appear. Portal vein stasis manifests as gastrointestinal symptoms, nausea and vomiting, anorexia, abdominal distension, etc. It can also manifest as jugular venous varices. When the albumin is too low, it will also first manifest as lower limb edema. So the lower extremity edema should go to the hospital inside the timely consultation, improve the examination, clear diagnosis and symptomatic treatment.