Final answer:
Excess fluid in the lungs leads to pulmonary edema, often due to heart failure, affecting gas exchange and potentially becoming life-threatening.
Step-by-step explanation:
Leakage of excess fluid in the lungs can lead to pulmonary edema, which is a condition characterized by excess fluid in the lung's air sacs. This can occur when heart failure causes fluid to get "backed up" in the pulmonary capillaries, due to the left ventricle's inability to pump sufficient blood into the systemic circulation. As a result, increased hydrostatic pressure within the pulmonary capillaries forces fluid out of the blood vessels and into lung tissues, compromising gas exchange and leading to symptoms such as difficulty breathing and chest pain. If not treated promptly, pulmonary edema can be life threatening.