Infection with respiratory syncytial virus (RSV) is common among young children and usually begins as a mild cold, but can cause severe breathing problems in premature babies, as well as infants and toddlers under the age of two who have chronic lung disease and chronic heart disease. Early symptoms include coughing, sneezing, fever and runny nose, making RSV very difficult for parents to distinguish early on from a common cold.

Here are some signs to look out for if you suspect your child’s cold may be more serious:

1. Difficulty breathing

After one or two days, the virus can travel to the lungs, affecting the small airways (called bronchioles) that allow your child to breathe easily. Once the airways are affected you may begin to notice faster breathing, flaring of the nostrils, sinking of the neck and sucking in of the ribs while breathing. These are indicators that your child is having difficulties moving air into and out of the lungs and needs to be seen by a doctor.

2. Unusual behavior

RSV may cause your child to be more irritable, sleepy or uncomfortable than normal. Another cause for concern may be if your baby is not feeding well.

Preventing RSV can be very difficult, especially because it is spread in droplets of fluid from sneezing, coughing or laughing. Since the virus travels and lives on surfaces, washing your hands often and keeping infants away from children and adults who are exhibiting common cold symptoms can be extremely helpful. Breastfeeding and avoiding second hand smoke also show natural benefits to possibly preventing RSV.