In most cases, the dark circles under the eyes are blood vessels that can be seen through the skin. The skin around the eyelids (periodontal skin) is the thinnest skin in the body (around 0.5 mm thick compared with 2 mm in other areas). Like varicose veins, dark circles under the eyes are usually an inherited trait. When blood passes through the large veins close to the surface of the skin, it can produce a bluish tint. The more transparent the skin—also an inherited trait—the darker the circles appear. In people with a deep-set bone structure, shadowing can also contribute to the dark color 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 fever sufferers in particular 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.
Any medications that cause blood vessels to dilate can cause circles under the eyes to darken. Because the skin under the eyes is very delicate, any increased blood flow shows through the skin.
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. It is believed that a lack of mineral iron can cause dark circles as well. Iron deficiency is the most common type of anemia and this condition is a sign that not enough oxygen is getting to the body tissues.
The skin can also become more pale during pregnancy and menstruation (due to lack of iron), allowing the underlying veins under the eyes to become more visible.
A lack of sleep or excessive tiredness can cause paleness of the skin, allowing the blood underneath the skin to become more visible and appear bluer or darker.
Dark circles under eyes can be symptom of liver disease.
Dark circles are likely to become more noticeable and permanent with age. This is because as people get older, their skin loses collagen, becoming thinner and more translucent. Circles may also gradually begin to appear darker in one eye than the other as a result of some habitual facial expressions, such as an uneven smile.
When to see a doctor
If discoloration and swelling appear under just one eye and seem to get worse over time, talk to your primary care doctor.
Depending on what’s causing the circles under your eyes, your doctor may recommend prescription creams or a combination of treatments to erase or reduce discoloration. Laser therapy or chemical peels can be helpful in some cases. Hollows that cause shadows can be smoothed with injectable fillers, and surgery can eliminate puffy lids.
However, dark under-eye circles usually aren’t a medical problem, and home remedies for dark circles under eyes may be all you need to help manage this condition.
Mild to moderate dark circles often respond well to simple and inexpensive treatments, such as:
Cold: Try a cold compress, two chilled teaspoons or a bag of frozen peas wrapped in a soft cloth to temporarily reduce dilated and discolored under-eye blood vessels. Or try a cooled, used teabag.
Extra pillows: Elevate your head with two or more pillows to prevent puffiness that develops when fluid pools in your lower eyelids.
Extra sleep:. Although short nights don’t usually cause under-eye circles, a lack of sleep makes you paler and more hollow-eyed, so shadows and circles you already have are more obvious.
Dark glasses and sunscreen: Although a tan might hide dark circles in the short term, in the long run, the extra pigment it produces can make circles worse.
Saline washes or sprays Rinsing your sinuses with a saltwater solution (mix 1/4 teaspoon sea salt with 2 cups warm water) or over-the-counter saline spray can help relieve nasal congestion.
Cosmetics: Hundreds of skin creams that claim to reduce or prevent under-eye circles crowd department store and drugstore shelves. The results of one study showed that a serum containing plant-based compounds, including root extracts and Brazilian sums, significantly improved the appearance of dark under-eye circles.
Camouflage: The right concealer can do just that — hide dark circles. If the circles under your eyes are bluish, use a peach-colored concealer, not one that’s white or gray. And avoid scented products and those containing salicylic or glycol acid, which can irritate delicate eye tissue, making redness and swelling worse.