Have you gazed in the mirror lately only to see someone with that old, tired look? For many of us, the single facial feature that ages us most is having dark circles under our eyes. Although these dark circles most commonly appear in healthy individuals who are not suffering from illness or exhaustion, they can still make us feel old, sick, and tired. Or just plain sick and tired.

Dark circles under the eyes affect both men and women, and can be present in children, though they most often develop sometime in adulthood. The secret to getting rid of the darkened skin is to identify the cause. Unfortunately, there are many, many causes–which may explain why so many eye creams don't actually seem to work! Using the wrong treatment can be an expensive (and occasionally unsafe) waste of time.

The first defense against those dark circles is to get plenty of sleep, avoid smoking and excessive alcohol use, and maintain a healthy diet. Taking your vitamins, particularly Vitamins C and E, can help, too. That said, the most common causes of circles below the eyes, according to the Mayo Clinc, are

Allergies (which can also cause nasal congestion, leading to dilated and darkened veins that drain from your eyelids to your nose)

Eczema

Genetics (those dark circles can run in families)

Lifestyle (alcohol, caffeine intake, smoking are some of the more extreme examples)

Excessive salt intake or genetic predisposition can also lead to swelling below the eyes, especially in mornings after lying down all night

Tendency for skin hyperpigmentation (darkening), especially in African-Americans and Asians

Tanning or excessive sun exposure without the use of protective sunscreens or sun block

Aging, leading to thinner skin from fat and collagen type III loss, allowing the purplish blood vessels in the muscle beneath the skin to show through.

There are also a large number of more serious medical reasons for skin pigmentation. Fluctuations in the level of thyroid hormone present in your body may be one such reason. Visiting your doctor and a facial plastic surgeon to be certain that those dark circles under your eyes are simply a cosmetic concern is always a great idea.

In the next entry, I'll discuss some treatments for specific causes of dark circles that can be done with physician supervision or right in the office with minimal, if any, downtime.