Car sickness is a type of motion sickness. Motion sickness occurs when the brain receives conflicting information from the inner ears, eyes, and nerves in the joints and muscles.

Imagine a young child sitting low in the back seat of a car without being able to see out the window — or an older child reading a book in the car. The child's inner ear will sense motion, but his or her eyes and body won't. The result might be an upset stomach, cold sweat, fatigue, loss of appetite or vomiting.

It's not clear why car sickness affects some children more than others. While the problem doesn't seem to affect most infants and toddlers, children ages 2 to 12 are particularly susceptible.

To prevent car sickness in children, you might try the following strategies:

• Reduce sensory input. Encourage your child to look at things outside the car rather than focusing on books, games or screens. If your child naps, traveling during nap time might help.
• Carefully plan pre-trip meals. Don't give your child a large meal immediately before or during car travel. If the trip will be long or your child needs to eat, give him or her a small, bland snack — such as dry crackers and a small drink — before it's time to go.
• Provide air ventilation. Adequate air ventilation might help prevent car sickness.
• Offer distractions. If your child is prone to car sickness, try distracting him or her during car trips by talking, listening to music or singing songs.
• Use medication. If you're planning a car trip, ask your child's doctor about using an over-the-counter antihistamine, such as dimenhydrinate (Dramamine) or diphenhydramine (Benadryl), to prevent car sickness. Both medications work best if taken about an hour before traveling. Read the product label carefully to determine the correct dose and be prepared for possible side effects, such as drowsiness. Nondrowsy antihistamines don't appear to be effective at treating motion sickness.

If your child starts to develop car sickness, stop the car as soon as possible and let your child get out and walk around or lie on his or her back for a few minutes with closed eyes. Placing a cool cloth on your child's forehead also might help.

If these tips don't help or if your child's car sickness makes travel difficult, talk to your child's doctor about other options.