Alveolar abnormalities are changes in the tiny air sacs in the lungs, called alveoli. Alveoli allow oxygen to enter the blood. They are very thin to let oxygen move from the lungs to the blood vessels, and for carbon dioxide to be removed from the blood vessels to the lungs.
Depending on the disease, alveoli may:
Develop thickened linings
Fill with fluid
Fill with blood
Fill with pus
Albertine KH. Anatomy of the lungs. In: Mason RJ, Broaddus VC, Martin TR, et al., eds. Murray and Nadel's Textbook of Respiratory Medicine. 5th ed. Philadelphia, PA: Elsevier Saunders; 2010:chap 1.
Denis Hadjiliadis, MD, Assistant Professor of Medicine, Division of Pulmonary, Allergy and Critical Care, University of Pennsylvania, Philadelphia, PA. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.