Bronchiolitis is when the tiniest air passages in your baby’s lungs become swollen. This can make it more difficult for your baby to breathe. Usually, bronchiolitis is caused by a virus called respiratory syncytial virus (known as RSV).
Almost all children will have had an infection caused by RSV by the time they are two years old. It is most common in the winter months and usually only causes mild ‘cold-like’ symptoms. Most children get better on their own.
Some babies, especially very young ones, can have difficulty with breathing or feeding and may need to go to
The virus that causes bronchiolitis in babies also causes coughs and colds in older children and adults so it is very difficult to prevent.