If there is a pleural effusion, fluid has accumulated between the lungs and the chest wall. A pleural effusion can lead to shortness of breath, a slightly elevated body temperature and even fever. The examination findings often show a reduced breathing sound.
The pleura is the pleura that extends over the lungs. The pleura consists of two leaves, an inner and an outer leaf. The inner leaf (pleura visceralis) is located on the surface of both lungs, while the outer leaf (pleura parietalis) lines the inner walls of the thorax, the top of the diaphragm and the pericardium, thus separating the lungs from the adjacent structures.
Between the two leaves is a fluid-filled cavity, the pleural gap, in which a negative pressure is created, preventing the lung from collapsing. The pleural gap usually contains five to ten milliliters of fluid. If more fluid accumulates there, it is a pleural effusion. The pleura absorbs about ten milliliters of fluid daily and also produces about ten milliliters of new fluid again. If this balance is disturbed, a pleural effusion occurs.
Causes
There are various possible causes for the development of a pleural effusion. The most common are malignant tumors (especially lung tumors), bacterial pneumonia or tuberculosis. Pleural effusion can also occur in diseases that do not primarily affect the lungs, such as malignant diseases of other organs or heart, kidney and liver diseases, as well as rheumatic diseases.
Malignant tumors make up the largest part of the triggers, they are responsible for about half of all pleural effusions, so that the pleural effusion must always be clarified to a malignant (malignant) underlying disease. The second most common cause is bacterial pneumonia with a share of about 30%. Every tenth pleural effusion is caused by heart failure.
If the pleural effusion occurs in the course of pneumonia, the inflammation can also spread to the effusion, so that the fluid is usually purulent during the puncture. In this case, the typical symptoms such as shortness of breath and fever then occur much more severely. If a purulent pleural effusion then develops in the course of the inflammation, this is referred to as a pleural empyema.
