You weren't up all night partying and you didn't pull an all-nighter to finish a big report. Unfortunately, you look like you did because you have dark circles under your eyes. These dark circles are actually hyper-pigmented areas that make that spot under your eye look darker than the skin that surrounds it. Shadows may appear in the hollows underneath your eyes due to your bone structure or develop as you age and your skin gets thinner. Your genes may also play a role -- sometimes shadows and pigmentation are hereditary and can be more common in certain races [source: Mayo Clinic].
Don't foist all the blame on your defenseless ancestors just yet. The harsh truth is that dark circles may reveal more about your lifestyle than you'd like. For instance, drinking alcohol and smoking cigarettes can cause them; even overindulging in caffeinated sodas can lead to those raccoon-like rings. Sunbathers need to be especially careful because melanin -- the substance responsible for skin pigmentation -- can darken the delicate area under the eyes [source: Mayo Clinic].
Although they're not usually considered a serious medical condition, these dark circles can be a sign of something more severe than sleep deprivation. For example, some allergists believe that they're actually a symptom of asthma; parents may use their appearance as a sign that their child is about to have an asthma attack [source: CDC]. Sleep disorders also can cause dark circles, as can certain medications designed to dilate blood vessels. They also may indicate a vitamin K deficiency [source: DocShop].
If the circles are purely cosmetic, then you're in luck -- there are treatments available that will keep you from looking like a linebacker. Read on to discover a common kitchen item that will aid you in your quest for a well-rested look.