A combination of a number of conditions, croup is an upper respiratory infection that causes a person's upper airways to become inflamed. Consequently, such inflammation causes a distinct cough that sounds like barking.
The people most susceptible to croup are three-month-old infants to children up to five years old.MedlinePlus: Medical Encyclopedia: Croup
Croup can be caused by either viruses or bacteria. However, croup of a viral origin is the most common.MayoClinic.com: Croup: Causes
Most Common Viral Causes
Disclaimer
The content in this page is not a substitute for professional medical advice. If you think you or someone you know has croup, please consult a physician.