When people see dark circles under a child's eyes, they usually think that the child isn't getting enough sleep or is in poor health. Actually, neither is usually the case.

The most common cause for dark circles under a child's eyes is allergies. The nasal congestion caused by an allergy leads to increased blood flow under the eyes. In fact, we often call them "allergic shiners."

Heredity can also cause these dark circles. Some people simply have thinner skin under their eyes. When I look at the parents of kids with dark circles, I often see that they have them as well!

Other causes of dark circles under eyes in kids include:

• Chronic sinusitis
• Blockage of the nose from large adenoids
• Recurrent colds
• Eczema or other conditions that can cause thinning of the skin

Call your doctor if your child has any of the following:

• Nasal congestion that won't go away
• Breathes through his or her mouth a lot
• Snores badly at night
• Has persistent skin irritation on her face (or anywhere else)

But chances are that the dark circles are nothing to be worried about.