Dark circles under the eyes have several distinct causes, and most people have more than one working against them at the same time. Dermatologists classify them into four main types: pigmented (brown), vascular (blue to purple), structural (shadow-based), and mixed. Understanding which type you’re dealing with is the first step toward actually improving them.
The Four Types of Dark Circles
Not all dark circles look the same, and the color and pattern can tell you a lot about what’s behind them.
Brown circles come from excess melanin, the pigment that colors your skin. This is especially common in people with deeper skin tones and often runs in families. Sun exposure makes it worse because UV light triggers more pigment production in the already-vulnerable under-eye area.
Blue or purple circles are vascular, meaning they come from blood vessels showing through the skin. You’ll typically notice these most on the inner corner of the lower eyelid, where the skin is thinnest and tiny capillaries sit close to the surface. When blood pools or vessels dilate, the area takes on a bluish tint.
Shadow-based circles aren’t really a color change at all. They’re created by the anatomy of your face: a deep tear trough (the groove running from the inner eye toward the cheek), under-eye bags, or puffy eyelids can cast shadows that make the area look darker than it actually is. Pulling the skin taut in a mirror is a quick test. If the darkness disappears, it’s likely structural.
Most people have a mix of two or more types, which is why a single product or remedy rarely fixes the problem completely.
Why the Under-Eye Area Is So Vulnerable
The skin under your eyes is fundamentally different from the rest of your face. It contains less subcutaneous fat, fewer oil glands, and less collagen, making it thinner and more translucent. That’s why blood vessels, fluid buildup, and pigment changes show up here first, even when the rest of your skin looks fine.
As you age, your body produces less collagen, and the already thin skin under your eyes gets even thinner and drier. The small amount of fat padding the area also diminishes over time, which can make the hollow between your eye and cheek more pronounced. The result is a combination effect: veins become more visible through the thinning skin, and the loss of volume creates shadows. This is why dark circles tend to worsen with each decade, even in people who never had them as teenagers.
Genetics and Skin Tone
For many people, dark circles are largely inherited. If your parents had them, you’re more likely to develop them too, regardless of how much sleep you get or how well you take care of your skin. Genetics influence how much melanin your body deposits around the eyes, how thick or thin your skin is in that area, and how deep your tear trough sits.
People with darker skin tones are more prone to the pigmented type because their skin naturally produces more melanin, and the under-eye area often produces it in higher concentrations than surrounding skin. Certain conditions involving increased pigmentation around the eyes also have a genetic basis and tend to appear in specific ethnic groups more frequently.
Allergies and Sinus Congestion
If your dark circles get worse during allergy season, there’s a clear physiological reason. When your immune system reacts to allergens, the moist lining inside your nose swells. That swelling slows blood flow through the veins near your sinuses, and those veins happen to run right beneath the skin under your eyes. When they become engorged, the area looks darker and puffier. Doctors sometimes call these “allergic shiners.”
This isn’t limited to seasonal allergies. Chronic sinus congestion from dust mites, pet dander, or food sensitivities can keep those veins swollen year-round. Rubbing itchy eyes also contributes by irritating the delicate skin and triggering post-inflammatory pigmentation, where the skin darkens in response to repeated friction or inflammation.
Sleep, Stress, and Daily Habits
Sleep deprivation doesn’t directly stain the skin, but it makes existing dark circles far more noticeable. When you’re tired, blood vessels under the eyes dilate, and the skin can look paler overall, which increases the contrast between your face and the darker under-eye area. Fluid can also pool beneath the eyes overnight when you sleep poorly or don’t sleep enough, adding puffiness that casts shadows.
Other lifestyle factors that contribute include dehydration (which makes skin look more sunken and hollowed), excessive alcohol consumption (which dilates blood vessels and disrupts sleep), smoking (which accelerates collagen breakdown), and prolonged screen time, which can cause eye strain and increased blood flow to the area. None of these are the sole cause for most people, but they can tip the balance from “barely noticeable” to “clearly visible.”
Iron Deficiency and Nutritional Gaps
When your body doesn’t have enough iron, your red blood cells carry less oxygen. That means less oxygen reaches the skin, and the already-thin under-eye area can look noticeably paler or darker as a result. The reduced oxygen also makes the tiny blood vessels beneath the surface more visible. If your dark circles came on relatively suddenly and you’re also experiencing fatigue, shortness of breath, or unusually pale skin, iron deficiency anemia is worth checking with a blood test.
Other nutritional deficiencies and hormonal disturbances can also play a role, though they’re less common causes than genetics, aging, or allergies.
What Actually Helps
Because dark circles have different root causes, the most effective approach depends on your specific type.
For pigmented (brown) circles, sun protection is non-negotiable. A broad-spectrum sunscreen applied daily to the under-eye area helps prevent further melanin production. Topical ingredients that address pigmentation, like vitamin C and niacinamide, can gradually lighten the area over weeks to months.
For vascular (blue/purple) circles, caffeine-based eye creams can temporarily constrict blood vessels and reduce puffiness. One clinical study tested a gel combining vitamin K, retinol, and vitamins C and E on under-eye circles and found it fairly or moderately effective in 47% of patients, with most of the improvement coming from reduced blood pooling. Cold compresses work on the same principle by constricting vessels, though the effect is short-lived.
For structural circles caused by volume loss or a deep tear trough, topical products have limited impact because the issue is anatomical rather than skin-deep. Dermal fillers placed in the tear trough can restore lost volume and reduce shadowing. Retinol applied consistently over months can modestly thicken the skin by stimulating collagen production, but it won’t reshape the underlying bone structure.
For allergy-related circles, treating the underlying congestion is the most direct fix. Antihistamines reduce the nasal swelling that backs up blood flow, and keeping allergies well-managed prevents the cycle of congestion, vessel dilation, and eye rubbing that makes things progressively worse.
Getting enough sleep, staying hydrated, and sleeping with your head slightly elevated (to reduce overnight fluid pooling) are baseline habits that help across all types. They won’t eliminate dark circles with a genetic or structural basis, but they reduce the additional factors that make them look worse on any given day.