What causes dark eye-circles?

What causes dark under-eye circles
Your shiners, your raccoon eyes, your blue luggage... whatever you call your dark under-eye circles, here's what they really are: oxidizing hemoglobin.

Dark under-eye circles begin in the capillaries, the tiny blood vessels that web the delicate skin around the eyes. Now, your capillaries are so small that red blood cells sometimes have to line up, single file, to get through. Frequently, red blood cells get lost and wander into the surrounding skin. This isn't a problem - it happens all the time - and your body has a mechanism to mop up these escapees. Enzymes in your body break down the red blood cells, including their hemoglobin (the molecule that gives them their distinctive red color). No problem, right? Except for one thing: when hemoglobin is broken down, its remaining components have a dark blue-black color. Just like a bruise. So your dark under-eye circles are actually caused by leaky capillaries.



How dark under-eye circles are like bruises:
When something hits you, blood vessels are traumatized and sometimes broken. Blood leaks out into the surrounding skin. Your body begins the mopping-up process, and you see a dark, purplish or blue-black discoloration.
So, as you can see, dark under-eye circles are very similar to bruises. The same mechanisms produce them.


Why are dark under-eye circles so visible?
It's quite possible that capillaries all over your body are leaking small amounts of blood all the time (I don't know if this is true or not). But the reason dark under-eye circles are so apparent is this: the skin around the eyes is some of the thinnest, most delicate skin of your entire body. The capillaries are much closer to the surface of the skin there. Many people's skin is not only thinner around the eyes, but also more translucent.
The combination of capillaries near the skin's surface and translucent skin makes this discoloration much more apparent. And that's why you have those dark under-eye circles staring back at you in the mirror.

Some other causes:

Age: Dark Eye CircleThe skin below our eyes is thin and is not as well endowed with oil glands as the rest of the body. Consequently as we age, the skin gets dry and wrinkled. As a result, the veins in the lower eye area appear more prominent. This results in dark circles under the eyes.

Heredity – Dark under eye circles are often an inherited trait. Those who are prone to allergies or itchy skin condition are susceptible to dark circles since inflammation and rubbing of eyes can thicken and darken the skin around them.

Lack of Sleep – Lack of sleep and fatigue can cause the skin to grow wan and pale. This makes blood vessels under the eyes to appear more visible and dark. The paleness that occurs with fatigue, a cold or sinus infection or during menstruation or pregnancy may accentuate the circles under the eyes.

Bone Structure – Deep set eyes may have a tendency to develop dark shadows under them. In fair-skinned persons, dark eyes become more obvious.

Sun Exposure – Increased exposure to the sun can draw pigmentation the skin’s surface and create dark circles.

Medication – Drugs that cause blood vessels to dilate may result in darkening circles around the eyes.

Nutrition – Dark circle around the eyes can be the result of poor nutrition.

Hormonal Changes – Since the skin undergoes changes during pregnancy and menstruation, you may notice darkening of the circles under the eyes.