This cold and flu season is hitting us really hard this year, and that can be confusing for parents. How can you tell when your kid's cough or runny nose is something to really worry about? Coughing, congestion, runny nose...these symptoms can last for weeks and can be normal for kids. When should you go to the doctor? Pediatrician Dr. Alanna Levin says parents should bring their kid to the doctor if they get a fever late in their illness or it comes back, worsening nasal symptoms after 10 days, increase cough frequency, or ear pain.