Which condition involves fluid accumulation in the lungs?

Pulmonary edema is characterized by an accumulation of fluid in the lungs, which can severely impair gas exchange and lead to respiratory distress. This condition often arises due to heart failure, where the heart is unable to pump blood efficiently. As a result, blood backs up in the veins and leads to increased pressure in the pulmonary capillaries, causing fluid to leak into the alveoli, the tiny air sacs in the lungs.

When this fluid fills the alveoli, it can result in symptoms such as shortness of breath, a feeling of suffocation, and decreased oxygen levels in the bloodstream. This is a critical and potentially life-threatening condition that requires prompt medical intervention, often including oxygen therapy and diuretics to reduce fluid overload.

In contrast, while other conditions like bronchitis, epiglottitis, and pneumonia can affect the lungs, they do not involve the same mechanism of fluid accumulation seen in pulmonary edema. Bronchitis primarily involves inflammation of the bronchial tubes, epiglottitis is the inflammation of the epiglottis which can obstruct airflow, and pneumonia involves infection that causes fluid in the air spaces of the lungs but is typically due to infectious agents rather than a primary issue of fluid control within the bloodstream.