As we go about our daily lives, we all experience moments of fatigue or stress. These experiences can sometimes leave us with unsightly dark circles under our eyes, a tell-tale sign of exhaustion. But why do these circles form, and what can we do to get rid of them?

Dark circles under the eyes, or periorbital dark circles as they’re formally referred to by doctors, are first and foremost usually sign of fatigue. When we don’t get enough sleep, our bodies produce more cortisol, a hormone that can break down collagen, the protein that gives skin its elasticity. This can lead to puffiness and discoloration under the eyes.

Periorbital dark circles are very conspicuous because the skin around the eyes is the thinnest in all the body, around four times thinner than the rest of the body to be more precise.

Since the skin is so thin, blood vessels are easily seen through it. This is why a bruise around the eyes shows worse than any other place on the body — you’re seeing the ruptured blood vessels under the skin.

Similarly, it’s the blood flowing around your eyes that causes the dark-blue circles. Even though blood isn’t blue, the skin only allows violet wavelengths of light to pass through, so only blue light is reflected back to hit the retina, making the area around the eyes look bluish. People with darker skin tend to have veins that appear green or brown. As an oddity, people with very light skin, such people with albinism, will have dark circles that appear dark red or dark purple, which more closely resembles the color of blood.

However, it’s not just fatigue that causes dark circles. There is, in fact, a myrriad of potential reasons.

As we age, skin becomes thinner all over the body and loses elasticity, especially around the eyes. Aging particularly affects the the soft, pillow-like tissue beneath the eye known as suborbicularis oculi fat, or SOOF. As this special tissue shrinks and descends, the natural volume of the undereye decreases, casting a shadow below the eye. This is why older people have prominent periorbital dark circles, even when they might be well rested.

Another common cause of dark circles is dehydration. When we’re dehydrated, our bodies retain water in an effort to conserve it. This can cause puffiness under the eyes, making them appear darker than usual. Additionally, when we’re dehydrated, our skin can become dry and dull, which can exacerbate the appearance of dark circles. This is why lifestyles factors like smoking or drinking alcohol can lead to dark circles due to the subsequent dehydration. Exposure to sunlight and pollution can also cause damage to the skin, leading to inflammation and discoloration.

Some people are genetically predisposed to have dark circles all the time, young or old, because of a condition known as periorbital hyperpigmentation. The condition causes the skin below the eyes to produce more melanin —  the pigment that gives human skin, hair, and eyes their color — resulting in it appearing darker.

Periorbital hyperpigmentation doesn’t pose any medical risks, “however the development of dark circles under the eyes at any age is of great aesthetic concern because it may depict the individual as sad, tired, stressed, and old,” wrote dermatologist Roberts WE. He adds that the condition, which mostly affects people with darker skin, is challenging to treat, complex in pathogenesis, and lacks straightforward and repeatable therapeutic options, which is why many turn to cosmetics to cover up the skin around the eyes.

Allergies can cause inflammation in the body, leading to puffiness and discoloration under the eyes. Additionally, allergies can cause rubbing and scratching of the eyes, which can lead to further irritation and discoloration.

Other conditions that may cause dark circles:

• Nasal congestion
• Medical conditions (eczema, thyroid problems, etc.)
• Venous congestion in under eye blood vessels
• Environmental exposure
• Heredity

Lifestyle choices can also lead to prominent dark circles around the eyes. These may include:

• Smoking
• Hyperpigmentation caused by sun damage
• Caffeine consumption
• Alcohol consumption
• Sleep deprivation
• Dehydration
• Dietary deficiencies

How to get rid of dark circles

If you’re struggling with dark circles under your eyes, there are a few things you can do to reduce their appearance. One of the most effective treatments is getting enough sleep. Aim for at least seven hours of sleep per night, and try to maintain a regular sleep schedule. This can help reduce cortisol production and give your skin time to repair itself.

Another effective treatment is staying hydrated. Drink plenty of water throughout the day to keep your body hydrated and your skin looking fresh. Additionally, eating a healthy diet that’s rich in fruits and vegetables can provide your body with the vitamins and minerals it needs to keep your skin looking healthy and vibrant.

If your dark circles are caused by allergies, it’s important to treat the underlying allergy. This may involve taking antihistamines, avoiding allergens, or using a cool compress to reduce inflammation and puffiness.

There are also a variety of cosmetic treatments available for dark circles. One of the most popular treatments is topical creams that contain ingredients like caffeine, retinol, hyaluronic acid, or vitamin C, which can help reduce puffiness and brighten the skin.

Raccoon eyes

Hand in hand with dark circles is periorbital puffiness, the dreaded saggy bags below the eyes. Allergies, excessive salt consumption, and diseases like the flu cause fluid to build up below the eyes. The saggy bags exert more pressure on the skin and blood vessels surrounding the eyes making dark circles appear even more prominent.

Nothing comes close, however, to periorbital ecchymosis, also known as “raccoon eyes” or “panda eyes”. This condition typically occurs when a person suffers a nasty blow to the head, and the resulting skull fracture causes blood to flood the soft tissue around the eyes. Sometimes cancer may be involved. Raccoon eyes are serious business and require urgent medical attention which often leads to surgery.

The bottom line: Dark circles under the eyes are a common condition that can be caused by a variety of factors, including genetics, lifestyle choices, and environmental factors. While there is no one-size-fits-all solution to this problem, there are a variety of treatments available that can help reduce the appearance of dark circles and improve the overall health and appearance of your skin.