Acute pleurisy mostly refers to bacteria entering the pleural cavity, which is a closed cavity between the lungs and the muscles of the outside ribs, for example, the lungs are the inner tire of a bicycle, the muscles and bones are the outer tire of a bicycle, and between the inner and outer tire is the location of the pleural cavity. Once the bacteria get into the pleural cavity, a series of symptoms will occur. In the acute phase of acute pleurisy, fever, chest pain, fatigue, and fatigue will occur. If acute pleurisy is accompanied by pleural effusion and the amount of pleural effusion is large, chest tightness, shortness of breath, and heaviness on one side will also occur. If these symptoms are definitely pleurisy, you need to go to a specialized hospital for a series of examinations, such as chest X-ray or chest CT, to observe whether there are lesions in the lungs and fluid in the chest cavity, etc. If there are findings, you need to be hospitalized to further find out the bacteria causing the inflammation and treat with different antibiotics according to different bacteria.