A blunted rib-diaphragm angle on the right side is a sign on a chest X-ray that usually indicates a small amount of pleural effusion in the right side of the chest. There are a number of reasons why a pleural effusion may occur, such as chest injury, following open heart surgery, hypoproteinemia, pneumonia or pleurisy, cardiac insufficiency, cirrhosis of the liver, and so on. Blunt rib-diaphragm angle often indicates that the amount of pleural effusion is relatively small, usually not more than 300 ml, which usually does not require invasive treatment, but only needs to be treated for the primary disease, as long as the primary disease is well treated, this point of fluid can be absorbed on its own. There are also rare cases, such as the pleura of the rib-diaphragm angle has adhesions, can also be presented on the X-ray film rib-diaphragm angle blunt performance.