Dark circles under your eyes usually come down to one of a few things: genetics, thin skin showing blood vessels underneath, allergies causing vein congestion, or lifestyle factors like poor sleep. Most people have more than one cause working together, which is why dark circles can be so stubborn. The good news is that once you identify your specific type, you can target it more effectively.
Your Under-Eye Skin Is Uniquely Thin
The skin under your eyes is some of the thinnest on your entire body, measuring less than a millimeter thick. That thinness means the blood vessels, muscles, and bone underneath are closer to the surface and more visible. In younger adults, the dermis (the structural layer of skin) around the eye measures roughly 834 micrometers. By age 60 and beyond, it thins to about 771 micrometers. That difference sounds small, but on skin that’s already paper-thin, even a slight reduction makes the underlying purple and blue blood vessels more obvious.
This is why dark circles often seem to appear or worsen in your 30s and 40s. You’re also losing fat and collagen in the under-eye area with age, which creates a hollow (called the tear trough) that casts a shadow and makes discoloration look deeper than it actually is.
Genetics Play a Bigger Role Than You Think
If your parents or siblings have dark circles, there’s a strong chance yours are hereditary. In one study of 200 patients with dark circles, 63% had a positive family history. Among those whose dark circles were classified as “constitutional,” meaning not caused by any secondary condition, 77% had a family member with the same issue. This constitutional type is the single most common form, accounting for over half of all cases in the study.
Hereditary dark circles are especially prevalent in people with deeper skin tones. Research found constitutional dark circles in 94% of Indian patients and 65% of Malay patients studied. If you have naturally more melanin in your skin, your body is more likely to deposit extra pigment in the thin under-eye area. This type of discoloration tends to look brown or dark brown rather than blue or purple.
How to Tell What Type You Have
There’s a simple test you can do at home. Gently stretch the skin under your eye with a finger and look in a mirror. If the dark color moves with the skin as you stretch it, the cause is excess pigment (melanin) in the skin itself. If the discoloration stays in place and looks bluish or purple when stretched, you’re seeing blood vessels showing through the skin. This distinction matters because each type responds to different treatments.
A brownish tint that moves with the skin points to pigmentation, common in people with darker skin tones or a family history of dark circles. A bluish or purplish tint that doesn’t move points to vascular causes: blood pooling or showing through thin skin.
Allergies and Sinus Congestion
If your dark circles get worse during allergy season, you’re dealing with what doctors sometimes call “allergic shiners.” The mechanism is straightforward: when your nasal passages swell from an allergic reaction, they slow blood flow in the veins around your sinuses. Those veins sit just beneath the surface of the skin under your eyes. When blood pools in them, the area looks darker and puffier. This is why antihistamines or nasal sprays that reduce sinus swelling can visibly lighten under-eye circles in people with allergies.
You don’t need full-blown seasonal allergies for this to happen. Chronic low-grade nasal congestion from dust mites, pet dander, or mold exposure can produce the same effect year-round.
Sleep, Stress, and Fluid Retention
Too little sleep is one of the most common triggers people notice, and the connection is real. Sleep deprivation causes blood vessels to dilate, making them more visible through thin under-eye skin. It also leads to fluid retention around the eyes, creating puffiness that casts shadows and makes discoloration look worse. Interestingly, too much sleep can cause similar fluid buildup.
Dehydration works differently but looks similar. When your body is low on water, the skin loses volume and the area under your eyes appears more sunken, making the hollow and shadow more pronounced. Alcohol, high sodium intake, and crying all shift fluid balance in ways that temporarily worsen under-eye appearance. Screen fatigue can contribute too: staring at screens for hours strains the tiny blood vessels around your eyes and increases blood flow to the area.
What Actually Works for Treatment
Topical Products
For pigmentation-based dark circles (the brown kind that moves when you stretch the skin), look for eye creams containing vitamin C, niacinamide, or kojic acid. These ingredients reduce melanin production over time. One study combining vitamin K with retinol found improvement in 93% of patients with under-eye circles, though results took consistent use over weeks.
For vascular dark circles (the blue or purple kind), caffeine-based eye creams are more useful. Caffeine constricts blood vessels and reduces fluid buildup. A clinical trial using an eye pad with 3% caffeine and 1% vitamin K showed a 16% reduction in dark circle appearance over 28 days, with 100% of participants seeing some improvement. That’s modest, but visible. Retinoids can also help by gradually thickening the dermal layer over months, making blood vessels less visible through the skin.
Cold Compresses and Simple Fixes
A cold compress, chilled spoons, or even cold tea bags can temporarily constrict blood vessels and reduce puffiness. This won’t fix the underlying cause, but it’s a quick improvement before an event or photo. Sleeping with your head slightly elevated helps prevent fluid from pooling around your eyes overnight, which is one of the simplest things you can try first.
Cosmetic Procedures
When dark circles are caused by volume loss (that hollow, shadowed look), hyaluronic acid filler injected into the tear trough can make a noticeable difference. Results typically last 8 to 12 months on average, though some studies have documented visible improvement persisting 18 months or even up to 24 months. The most common side effects are bruising, swelling, and occasionally a bluish-gray tint where the filler sits too superficially. Delayed complications like lumps or nodules can appear months later, averaging around 16 months after treatment. Serious risks like infection or vision problems are rare but possible, so this procedure should only be done by an experienced injector.
For pigmentation-based dark circles that don’t respond to topical treatments, chemical peels and laser treatments can reduce melanin deposits. These typically require multiple sessions and carry a risk of worsening pigmentation in darker skin tones, so they need to be approached carefully.
Causes That Are Easy to Miss
Iron deficiency is one of the most overlooked causes. When your body doesn’t have enough iron, it produces less hemoglobin, and the reduced oxygen in your blood makes it appear darker through the thin under-eye skin. If your dark circles came on gradually alongside fatigue or pale skin, it’s worth checking your iron levels.
Sun exposure accelerates both types of dark circles. UV light triggers melanin production (worsening pigmentation) and breaks down collagen (thinning the skin further). Wearing sunscreen on the under-eye area and sunglasses that block UV is one of the most effective preventive steps, especially if you’re prone to pigmentation.
Rubbing your eyes habitually, whether from allergies, dryness, or just a nervous habit, creates friction that triggers inflammation and post-inflammatory pigmentation over time. This is especially common in people with eczema or contact dermatitis around the eyes.