How long an elderly person can live with pleural effusion in general depends mainly on the cause of the pleural effusion. Therefore, the survival time of elderly people varies greatly depending on the cause of the pleural effusion. Elderly people with milder primary disease usually do not have a significant impact on survival time through active treatment, and can live for more than ten or twenty years, or even longer. However, in the case of malignant pleural effusion, the prognosis is relatively poor and, together with the lack of active treatment, may significantly affect the survival time of the elderly, which may be as short as a few months. The clinical occurrence of pleural effusion is mainly related to chest diseases or systemic diseases, so the etiological treatment is particularly important. Generally, for pleural effusion caused by infectious diseases such as pneumonia, tuberculosis and lung abscess, the impact on survival time is relatively small in the elderly with active anti-infective treatment. However, if systemic infections are present, or if the elderly are in poor health and are not actively treated at the same time, the survival time may also be shortened due to extensive systemic infections. Malignant pleural effusion is one of the common complications of advanced malignant tumor in the elderly. The effusion grows very fast, and the elderly often have severe respiratory difficulties due to the compression of large amount of effusion, which greatly affects the survival time and quality of life. In this case, the disease is relatively serious and requires active puncture, fluid extraction and drainage of pleural effusion. At the same time, it is recommended to actively treat the primary disease, and for those elderly people who have the conditions, they can follow medical advice to supplement the treatment with radiotherapy, chemotherapy, surgery, etc. However, there are many other causes of pleural effusion, such as congestive heart failure, constrictive pericarditis, rheumatic diseases, pulmonary infarction, liver cirrhosis, nephrotic syndrome, acute glomerulonephritis, etc. Therefore, the survival time of elderly people with different primary diseases varies greatly. It is recommended that elderly people with pleural effusion should be treated actively to prolong survival time and improve quality of life.