Dark circles

Dark circles are dark blemishes around the eyes. Also known as "bags under the eyes," there are many etiologiesto cause this symptom. For instance, by lack of sleep, by deficiency of vitamin k, by heredityand by bruising.

Causes

Heredity

Like varicose veins, dark circles under the eyes are usually an inheritedtrait. If you have dark circles, there is a good chance that others in your family also have them. The skin under the eye is very thin. When blood passes through the large veins close to the surface of the skin it can produce a bluish tint. The more transparent your skin -- also an inherited trait -- the darker the circles appear.

Bone structure

If you have deep-set eyes, shadowing contributes to the dark color under the eyes.

Pigmentation

Genetic hyper-pigmentation is a common form of dark circles. Even in darker skinned people, exposure to sunlight, especially during the summer months, can cause a higher-than-normal level of skin pigmentation(melanin) under the eyes. People get sun tans because exposure to the sun increases the natural pigmentation of the skin and draws that pigmentation to the surface. The same principle applies to the skin under the eyes.

Allergies, asthma, and eczema

Any condition that causes the eyes to itch can contribute to darker circles due to rubbing or scratching the skin around them. Hay feversufferers particularly will notice under-eye "smudges" during the height of the allergy season. Some food allergies can also cause the area under the eyes to appear darker.

Medications

Any medications that cause blood vessels to dilatecan cause circles under the eyes to darken. Because the skin under the eyes is very delicate, any increase blood flow shows through the skin.

Lack of nutrition

The lack of nutrients in the diet, or the lack of a balanced diet, can contribute to the discoloration of the area under the eyes.

Fatigue

A lack of sleep or excessive tiredness can cause paleness of the skin, which again allows the blood underneath the skin to become more visible and appear more blue or darker.

Pregnancy and menstruation

The skin can also become more pale during pregnancyand menstruation(due to lack of iron), which again allow the underlying veins under the eyes to become more visible.

Age

If you have a propensity to have dark circles under you eyes, as you grow older, they are likely to become more noticeable and permanent. Excess folds of skin under the eyes will also make dark circles more pronounced.

References

• http://allergies.about.com/od/darkcircles/a/aa071304.htm
• http://www.azcentral.com/style/articles/0702darkcircles.html

This article is licensed under the GNU Free Documentation License.
It uses material from the http://en.wikipedia.org/wiki/Dark+circles Wikipedia article Dark circles.