HARRISONBURG, Va. -- Respiratory Syncytial Virus is the leading cause of the common cold. RSV symptoms are confusing because doctors say it's easy to get confused with flu symptoms.

When RSV attacks the lungs, it's dangerous for newborns and elderly people. Doctor Greg Jesteadt with Harrisonburg Family Practice said there are certain symptoms you want to look out for.

If your child is really struggling to breathe, take their shirt off. If they're breathing in and you can see the skin in between their ribs being sucked up, you want to get them to a doctor as soon as possible.

Other symptoms include bluish-colored skin on the lips and nail beds. Dr. Jesteadt said to watch out because it's not always obvious.

"They can look very good until they crash so if you are really looking at a kid that you think is sick and parents generally have sort of an inborn radar on you know something's really not right here. If you're getting that feeling don't wait on them," Dr. Jesteadt said.

Most emergency rooms do have a test for RSV. However, many doctor's offices don't have the test available.

If you go to the doctors office and doctors recognize that your child may have it, they'll walk you through the next step.

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