Mayo Clinic - Pneumonia is an infection that inflames the air sacs in one or both lungs. The air sacs may fill with fluid or pus (purulent material), causing cough with phlegm
![Illustration of diseased human alveoli. The alveoli are air sacs in the lungs, at the ends of the bronchioles, that allow the exchange of carbon dioxi Stock Photo - Alamy Illustration of diseased human alveoli. The alveoli are air sacs in the lungs, at the ends of the bronchioles, that allow the exchange of carbon dioxi Stock Photo - Alamy](https://c8.alamy.com/comp/2DHN6EG/illustration-of-diseased-human-alveoli-the-alveoli-are-air-sacs-in-the-lungs-at-the-ends-of-the-bronchioles-that-allow-the-exchange-of-carbon-dioxi-2DHN6EG.jpg)
Illustration of diseased human alveoli. The alveoli are air sacs in the lungs, at the ends of the bronchioles, that allow the exchange of carbon dioxi Stock Photo - Alamy
Breathe Better on X: "Pneumonia is an infection that causes the air sacs (called alveoli) in one or both lungs to fill up with fluid or pus. Find out how it can
![Diagram the pulmonary alveolus (air sacs) in the lung. The respiratory system lungs with detail of bronchioles and alveoli with capillary network. Alveoli structure Anatomy Stock Vector | Adobe Stock Diagram the pulmonary alveolus (air sacs) in the lung. The respiratory system lungs with detail of bronchioles and alveoli with capillary network. Alveoli structure Anatomy Stock Vector | Adobe Stock](https://as2.ftcdn.net/v2/jpg/01/51/79/31/1000_F_151793189_WrzqL1tNBvV87w5RRCUixtRtwYWaYgpu.jpg)