Becoming a parent for the first time is amazing, but it can also be scary -- especially the first time your baby gets sick. It can be tempting to hit the panic button for every little cough or rash. How can you tell what's serious, what's just new parent jitters, and what can wait until your baby’s next checkup? Here are six serious symptoms in babies that you should never ignore. **1. Blue Lips or Skin (Cyanosis)**: If your baby’s lips or skin turn blue, it means they are not getting enough oxygen. Call 911 immediately. **2. Strained Breathing**: If your baby’s breathing is consistently hard and fast, and you see their chest muscles working more than usual or their nostrils flaring, it may be a sign of respiratory distress. Call your pediatrician right away or go to the emergency room if it’s after-hours. **3. Fever**: If your infant is less than three months old and has a rectal temperature greater than 100.4 F, call your pediatrician. Fever in newborns can be serious and may require hospitalization and tests. **4. Jaundice**: If your newborn’s skin is getting yellower, it may be worsening jaundice. While some jaundice is normal, increasing levels need evaluation. Frequent feeding and phototherapy are common treatments. **5. Dehydration**: If your baby is not making wet diapers, it could be a sign of dehydration. Look for dry mouth, sunken eyes, and lethargy. Call your pediatrician for advice. **6. Vomiting**: Vomiting greenish bile or vomit that looks like dark coffee grounds can be serious. It may indicate intestinal blockage or internal bleeding. Vomiting after a head injury also requires immediate evaluation. In general, it's always better to be safe than sorry. When in doubt, always trust your gut and call your pediatrician.