Somehow, no matter how much sleep you get, you always look like you've pulled three all-nighters in a row. That's because fatigue isn't the only culprit behind dark circles under the eyes. Affecting both men and women, this common and persistent problem tends to crop up during adulthood and can stem from multiple causes. Before you even think about treatment options, it's important to investigate what might be responsible for the discoloration.
In many cases, dark circles are actually just shadows cast by puffy eyelids and under-eye bags. These can result from allergies, sinus infections, eating salty foods, drinking alcohol or anything else that leads to water retention, causing fluid to accumulate under the eyes [source: Bailly]. Bags also occur when you miss out on sleep and don't exercise regularly.
Sometimes, however, chronic dark circles reflect excess pigmentation of the skin. Did your mother or father also have raccoon eyes? Chances are you've inherited the condition. Sun exposure, which stimulates melanin production, can also trigger hyperpigmentation [source: Zezima].
If your dark circles have a bluish tinge and tend to lessen when you press on them, blood vessels showing through the skin could be to blame. The skin under the eyes is extremely delicate to begin with, and age-related collagen and fat loss thins it out even more over the years [source: Morrill]. "The thicker your skin is, the less visible the vessels will be," explains dermatologist Amy Wechsler. Chronic eye rubbing due to allergies or eczema can cause the blood vessels to dilate or bruise, becoming darker than usual [source: Danoff].
Finally, it may all come down to your bone structure, Dr. Wechsler notes. "Dark circles can also be caused by hollowness under the eyes," she says.