Pleural effusion caused by renal failure is usually more serious, at this time, protein malnutrition, heart failure, co-infection and so on may occur. Patients with renal failure, because of the retention of toxins can appear gastrointestinal symptoms, such as nausea and vomiting, loss of appetite, causing malnutrition; coupled with the damage to the renal parenchyma, there can be an increase in urinary proteins, so the body will have protein malnutrition, the osmotic pressure of the blood is changed, and the leakage of water into the cavity can form pleural effusion. The emergence of a large amount of pleural effusion, will cause the patient dyspnea, cardiac load, may appear heart failure; at the same time, renal failure patients, water, toxin discharge obstacles, will cause myocardial lesions and cardiac overload, with the progression of the disease, and the emergence of cardiac failure, which occurs in acute pulmonary edema, pleural effusion. Long-term pleural effusion is easily combined with infections, such as pneumonia and pleurisy. Patients with pleural effusion caused by renal failure are prone to various complications and comorbidities, so it is recommended to visit regular hospitals in time and standardize the treatment under the guidance of doctors.