Got those black circles?

If you have dark circles under your eyes you may want to check out the family tree. It turns out dark under-eye circles or bags may be inherited. Yes, one more thing you can blame on your parents.

Fatty tissue and fluid collect under the eyes but are more prominent in some people. These fat pads can swell and cast a shadow that gives the appearance of a dark circle. Extra pigmentation -- also inherited -- might also be to blame. Aside from genetics, fluid retention caused by medical conditions or certain drugs can also cause the area to swell more.

Another explanation for dark circles is the thinness of the skin underneath the eye. Skin in this delicate area is only half a millimeter thick -- practically transparent! And what's behind the skin is blood. If something irritates the blood vessels and causes them to dilate more, additional blood will be delivered to the area, causing an even darker appearance. Heat, hot food, sun damage and caffeine can all cause blood vessels to dilate. But so can allergens. The body reacts to allergens by bringing extra fluid, which then makes vessels swell. Simply treating allergies can lessen dark circles.

When all else fails, blame it on aging. As the skin thins and sags around the eyes, blood vessels become more apparent and the skin takes on a baggy appearance.

Resources:

Read more about dark circles and bags at The New York Times Learning Network and The Discovery Channel Online.