Your child's had a cold for a week now, and it's getting worse. His cough is wet and phlegmy, and his breathing seems to be faster than usual.
What's probably causing it: Pneumonia, in which a virus or bacterium invades the lungs, causing them to fill up with fluid. "Because the child is trying to get the fluid out of his lungs, a pneumonia cough tends to be pretty ugly," says Dr. Lonzer. "This is the hacking-up-goobers one."
How to help: Your pediatrician may be able to diagnose pneumonia with a physical exam but might need to send your child for an X ray. She may do an oxygen-saturation test (placing a bandage-like strip around your child's finger) to check for a low oxygen level. If the doctor determines from the test results that the pneumonia is bacterial, she'll prescribe antibiotics; viral pneumonia has to run its course. Pneumonia can usually be treated at home, but if it's severe, your child may need to stay in the hospital for a few days.