Fluid on the lungs in elderly is a condition called pulmonary edema, which is the abnormal buildup of fluid in the lungs. This fluid collects in the many air sacs in the lungs, making it difficult to breathe. The most common cause of pulmonary edema is congestive heart failure, which occurs when a diseased or overworked left lower heart chamber (left ventricle) cant pump out enough of the blood it gets from the lungs, causing pressures in the heart to go up and pushing fluid through the blood vessel walls into the air sacs. Other medical conditions that can cause heart failure and lead to pulmonary edema include coronary heart disease, blood clot in the lungs (pulmonary embolism), and viral illnesses. However, fluid can collect in the lungs for other reasons, such as pneumonia, exposure to certain toxins, medications, trauma to the chest wall, and traveling to or exercising at high elevations. Kidney disease is also a common cause of fluid in the lungs of older adults. The symptoms of fluid in the lungs vary depending on the cause of the fluid buildup, but the most common symptom is shortness of breath, which may worsen while lying down. If an elderly individual experiences fluid in their lungs, it is important to seek immediate medical attention.