What’s the difference between bronchiolitis and bronchitis?

What’s the difference between bronchiolitis and bronchitis?

These two conditions not only sound similar, but they are similar in some ways. Both can be caused by a virus. Both affect the airways in the lungs, but bronchitis affects the larger airways (the bronchi). Bronchiolitis affects the smaller airways (bronchioles). Bronchitis usually affects older children and adults, while bronchiolitis is more common in younger children.