Making the decision to call your pediatrician can sometimes be a tricky one, especially late at night. On one hand, you don't want to cry wolf -- bothering your doctor every time your child sneezes. On the other hand, you certainly don't want to miss any critical symptoms. Pediatrician Angela Thompson-Busch M.D., Ph. D., believes that it's better to err on the side of caution. "I think parents should let the doctor decide whether or not a trip to the doctor's office is necessary," she advises. Here, she helps you decide on the severity of your child's illness as well as the best course of treatment.

1. Vomiting: After an episode of vomiting, it is best to wait for one hour before allowing your child to drink anything. Then give your child a few small sips of clear liquid (electrolyte solution, soda pop, Popsicles). If this stays down for 15 minutes continue to give fluids in moderation every 15 minutes for at least four hours before progressing to food. When these measures don't work, the child may ultimately become dehydrated. Persistent vomiting for more than 24 hours should be evaluated by your child's doctor. This is especially true if there is no accompanying diarrhea. Vomiting and fever alone may be signs of a urinary tract infection, strep throat or appendicitis. If your child is having episodes of vomiting that are bloody, a thick green color or projectile, this could indicate an injury or a blockage in the bowel and should be considered a medical emergency. Learn more.