Dark circles under your eyes usually come down to one of four things: visible blood vessels showing through thin skin, excess pigment in the skin itself, a hollow or groove that casts a shadow, or some combination of all three. The skin under your eyes is the thinnest on your entire face, with a dermis measuring only about 759 microns compared to nearly 2,000 microns along the sides of your nose. That thinness makes everything underneath more visible, which is why this area shows color changes before anywhere else on your face.
The Four Types of Dark Circles
Not all dark circles look the same because they aren’t caused by the same thing. Dermatologists generally classify them into four categories, and knowing which type you have determines what will actually help.
Vascular: These look blue, purple, or pink and are caused by blood vessels visible through your thin under-eye skin. If you gently stretch the skin and see tiny capillaries or veins, this is your type. It’s especially common in people with fair or thin skin.
Pigmentary: These appear brown or dark brown and come from excess melanin deposited in the skin itself. When you stretch the skin, the dark color stays. This type is more common in people with deeper skin tones and can be triggered by sun exposure, genetics, or inflammation from conditions like eczema.
Structural (tear trough): These aren’t actually a color change at all. A groove or hollow under the eye creates a shadow that looks like a dark circle. You can test this by shining a light directly at the area. If the “darkness” disappears under direct lighting, it’s a shadow from lost volume, not a skin color issue.
Combination: Most people have more than one type happening at once. Studies from several countries consistently find that mixed-type dark circles are the most common presentation, affecting anywhere from 54 to 78 percent of people who seek treatment.
A Simple Test You Can Do at Home
Gently pinch and lift the skin under your eye while looking in a mirror. If the dark color lifts with the skin, it’s likely pigmentation. If the color disappears when you pull the skin away from the underlying tissue, it’s more likely blood pooling, thin skin letting vessels show through, or shadows from hollow areas underneath. This won’t give you a clinical diagnosis, but it helps you understand whether your dark circles are a skin-surface issue or something structural beneath the skin.
Why Thin Skin Makes It Worse
Your under-eye skin is thin to begin with, and it gets thinner over time. Collagen breaks down with age and sun exposure, and the fat pads that sit beneath your lower eyelids shift and shrink. As the ligaments holding those fat pads weaken, the tissue descends and creates a visible groove called a tear trough. That groove deepens the shadow under your eye while the thinner skin makes blood vessels more visible. This is why dark circles often seem to appear or worsen in your 30s and 40s even if you never had them before.
Genetics play a significant role in how thick your skin is, how much pigment you produce around your eyes, and how your facial fat is distributed. If your parents had dark circles, you’re more likely to have them too, regardless of how much sleep you get.
Allergies and Sinus Congestion
If your dark circles get worse during allergy season or when you’re congested, there’s a direct physiological explanation. When the lining of your nasal passages swells from allergies, it slows blood flow in the veins around your sinuses. Those veins sit close to the surface right under your eyes. When they swell with backed-up blood, the area looks darker and puffier. Doctors sometimes call these “allergic shiners.”
The key difference with allergy-related dark circles is that they fluctuate. They worsen when your allergies are active and improve when congestion clears. If your dark circles come and go with the seasons or respond to antihistamines, this is likely a major contributor.
Sleep, Dehydration, and Lifestyle Factors
Sleep deprivation doesn’t create dark circles from nothing, but it makes existing ones more obvious. When you’re tired, your skin looks paler, which increases the contrast with the blood vessels underneath. Fluid can also pool under your eyes when you’re lying down for long periods or not sleeping well, adding puffiness that creates shadows.
Dehydration has a similar effect. When your body is low on fluids, the skin under your eyes can look sunken, making the hollow more pronounced. Salt-heavy meals, alcohol, and smoking all contribute to fluid retention or vascular changes that worsen the appearance of the under-eye area. These factors don’t cause dark circles on their own, but they amplify whatever underlying tendency you already have.
What Skin Tone Has to Do With It
The dominant type of dark circle varies significantly across skin tones. In people with lighter skin, the vascular type tends to dominate because blood vessels show through pale skin more easily. In people with darker skin tones, pigmentary causes are more common, often driven by genetics or post-inflammatory changes from conditions like eczema or contact dermatitis around the eyes. A study from India found that constitutional (genetic) pigmentation accounted for over half of cases, with post-inflammatory pigmentation making up another 22 percent. This matters because treatments that work for vascular dark circles won’t help pigmentation, and vice versa.
Topical Treatments and What to Expect
Eye creams containing caffeine and vitamin K have some clinical support, though the results are modest. In one controlled trial, a pad containing 3 percent caffeine and 1 percent vitamin K reduced dark circle appearance by about 16 percent over four weeks, with most of the improvement happening by week three. Caffeine works by temporarily constricting blood vessels and reducing fluid retention, so it’s best suited for vascular-type dark circles. Vitamin K plays a role in blood clotting and may help reduce the appearance of visible blood pooling.
Retinol (vitamin A) can help over time by stimulating collagen production, which thickens the skin and makes vessels less visible. An older study found that vitamin K combined with retinol improved under-eye circles in 93 percent of participants. Vitamin C and niacinamide can help with pigmentary dark circles by inhibiting excess melanin production. Sunscreen is essential if pigmentation is your issue, since UV exposure triggers more melanin in the under-eye area.
The honest reality is that topical products produce gradual, partial improvements. They won’t eliminate dark circles, but they can meaningfully reduce their appearance if you match the product to your type.
Professional Treatment Options
For structural dark circles caused by a tear trough, hyaluronic acid fillers are the most common professional treatment. A small amount of filler is placed deep along the orbital rim to restore lost volume and smooth out the hollow. Results typically last 10 to 18 months, with some studies showing measurable volume improvement lasting over 14 months.
Fillers in this area carry specific risks. The most common side effects are bruising, swelling, and a blue-gray tint called the Tyndall effect, where the filler shows through thin skin. People with very light or thin skin are most susceptible to this discoloration. Delayed complications like small lumps or filler migration can appear months later. Rare but serious complications include infection and vascular events that can affect vision. This is one area where choosing an experienced injector matters enormously.
For pigmentary dark circles, chemical peels and laser treatments targeting melanin can help. For vascular types, certain lasers that target blood vessels may reduce the purple or blue tones. These procedures usually require multiple sessions.
When Dark Circles Signal Something Else
In most cases, dark circles are a cosmetic concern with a straightforward explanation. But sudden, bilateral puffiness under the eyes, especially paired with swelling in your feet, ankles, or lower back, can indicate kidney, heart, or liver problems. Hypothyroidism causes painless puffiness across the face along with dry skin, coarse hair, and cold sensitivity. Hyperthyroidism with Graves disease can cause a distinct staring appearance with prominent eyes, along with rapid heart rate and unexplained weight loss.
The distinguishing feature of systemic causes is that the swelling is typically painless, appears on both sides equally, and comes with other symptoms elsewhere in the body. If your under-eye changes appeared suddenly, are getting progressively worse without an obvious explanation, or are accompanied by swelling in other parts of your body, that pattern points toward something worth investigating beyond cosmetics.