The typical X-ray manifestation of pulmonary edema is called butterfly wing-like shadow, the shadow is like two large wings of a butterfly and two small wings below, bilaterally symmetrical. Pulmonary edema is usually diagnosed when a typical shadow appears, but more often atypical manifestations are encountered in clinical practice. For example, if an elderly patient with hemiplegia is habitually lying on his left side or on his right side, when pulmonary edema occurs, the part of the patient that is lying down is heavy and the part that is far from the bed is light, so it does not appear as symmetrical butterfly wing-like pulmonary edema, which is the most common X-ray manifestation that can be easily misinterpreted. There are also other atypical pulmonary edema on X-ray, which can be missed by professional physicians.