What are the main causes of sharp bilateral costophrenic angles?

The bilateral costophrenic angles are sharp. In most cases, this is a normal finding, but a comprehensive assessment should be made in conjunction with other examinations and symptoms. 1. Normal condition: A sharp costophrenic angle generally indicates there is no blood accumulation, fluid buildup, or adhesion of the pleura between the rib and diaphragm angle, and is considered a normal phenomenon. 2. Possible causes: Although sharp costophrenic angles mostly indicate normal conditions, in some situations—for example, if the patient is in a state of tension or if the costophrenic angle is overly full—examination results may contain errors. 3. Other factors: Even though sharp costophrenic angles indicate normal conditions, there may still be the possibility of other diseases, such as costochondritis or pleurisy, that have not yet manifested. Therefore, attention should also be given to other examination results and symptoms.