Illustrated Guide to Asthma Airway WebMD Medical Reference MEDICAL REVIEW: Reviewed by Michael W. Smith, MD, May 2004 SOURCE DOCUMENTATION: Scientific American Medicine, The Merck Manual, 17th edition LEGAL DISCLAIMER: This tool is for general information purposes only and does not address individual circumstances. It may not be right for you and should not be relied upon in making decisions about you health. Always consult your doctor for medical advice.