Recently, Susan, a wise yet exhausted mother, brought her 6-month-old baby to the office because she was concerned about his nonstop crying. "Nathan hasn't slept well since he was born," she said. "I'm up with him three or four times a night, and the only thing that settles him is nursing. He's fine during the day as long as I hold him a lot, but as soon as I put him down, he screams. I've been to four pediatricians and no one can help. I'm tired of people telling me I'm spoiling my baby by holding him too much, because I know something is wrong."

Her hunch turned out to be right. After delving into Nathan's medical history and looking at the notes his mom had kept, I suspected the baby was having severe pain from gastroesophageal reflux disease (GERD). Sure enough, a test quickly confirmed this diagnosis.

It's unfortunate that it can sometimes take so much time (and so many doctors) to get to the bottom of a child's health problem. The good news? There are things that you, as a mom, can do to speed up the process:

Listen to your mommy gut. No one knows a baby like his own mother does.

Take notes. When your child gets sick, write down his symptoms and anything else that seems relevant. (For more about specific symptoms, go to Parenting.com/childhealthguide.)

Team up with your pediatrician. Getting the best health care for your baby is a partnership between you and his doctor. Your role is to be a keen observer and accurate reporter; the doctor's role is to take what you report and make the right diagnosis.

Get a little medical training yourself. Some childhood health problems can be easy to overlook. What follows here are five of the most common ones -- plus what you need to know to help your doctor catch them.

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