What commonly causes fluid in the lungs?

Fluid accumulation in the lungs occurs due to two reasons:

  • Cardiogenic reasons where the heart fails to pump the blood to the systemic circulation, leading to build up of blood in the pulmonary circulation, which eventually leads to increased hydrostatic pressure and causes the fluids to leak from the capillaries into the lung itself.
  • Non-cardiogenic reasons where severe infections for example, leads to the release of a huge amount of inflammatory agents, leading to large amount of fluids to escape from the capillaries since they increase the capillary permeability causing fluid buildup in the lungs


Fluid on lungs, or "Pleural effusion" could have several causative factors.Chest X-ray, ultrasound, chest CT, are all useful for your doctor for determining the cause. Thoracentesis, removing/examining some of the fluid is also used.Among the many possible causes are- TB- infections of fungal or parasitic nature- Malignancy- Pulmonary embolism,- rheumatoid arthritis,- abdominal disease (like Pancreatis)- congestive heart failure- liver diseases (like cirrhosis, Nephrotic Syndrome, Hepatic Hydrothorax)- and many othersHepatic Hydrothorax is more common on the right side.More informations can be found on the related links.