CUMMING, Georgia (CNN) -- Kamryn Campbell is only 16 months old, but she's been through more medical trauma than most people will suffer in a lifetime.

Because Kamryn Campbell, with mom Stephanie, had RSV, she's at increased risk for asthma.

To start with, Kamryn was born seven weeks premature. She spent nearly a month in a neonatal intensive care unit to help her lungs develop. Two weeks after being released, she was rushed back to the hospital in an ambulance, struggling to breathe.

"She turned gray and she wasn't breathing at all," recalls her mother, Stephanie Campbell of Cumming, Georgia. After undergoing testing, Kamryn was found to have respiratory syncytial virus or RSV.

"For you and me it's a really bad head cold," says pediatric pulmonologist Burt Lesnick. "But for those children at risk it can be life threatening."

The American Academy of Pediatrics reports almost all children are infected with RSV at least once before they turn two years of age. Most of the time, the virus causes cold-like symptoms and no specific treatment is needed. For others, the infection is more dangerous.

Lesnick estimates one in 300 normal term babies will be hospitalized each year because of RSV. Premature infants fall into the high-risk category because of their underdeveloped lungs and difficulty in fighting infection. About one of every 30 preemies with RSV requires hospitalization.

The illness may start just like a cold with symptoms including a runny nose, cough and fever. Trouble sleeping and apnea may also be signs of RSV. Lesnick says that in many cases, RSV causes bronchiolitis, an inflammation of tiny airways called bronchioles, and viral pneumonia. A chest X-ray may be required to make a formal diagnosis.