Dark circles under the eyes are rarely a sign of illness. They’re usually caused by some combination of genetics, thin skin, visible blood vessels, and the natural shape of your face. What makes them frustrating is that multiple factors often overlap, which is why they can be so stubborn to address. Understanding what’s driving yours is the first step toward doing something about it.
Why Under-Eye Skin Shows Everything
The skin beneath your eyes is among the thinnest on your body. It has very little subcutaneous fat and sits directly over a web of tiny blood vessels, muscles, and ligaments attached to bone. This means anything happening just below the surface, whether it’s blood pooling, pigment accumulation, or volume loss, tends to show through visibly.
To make matters worse, this area thins further as you age. While most facial skin actually gets thicker over time (on the forehead, cheeks, and chin), the infraorbital region does the opposite. It loses what little cushioning it had, making dark circles progressively more noticeable in your 30s, 40s, and beyond.
The Four Types of Dark Circles
Not all dark circles look the same because they aren’t caused by the same thing. Clinically, they fall into four broad categories: pigmented, vascular, structural, and mixed. Most people have a combination, but one type usually dominates.
Pigmented
This type involves excess melanin deposited in the skin around the eyes. It’s the most common cause in people with deeper skin tones. One study of Indian patients found that constitutional pigmentation accounted for over half of all cases. It can run in families, worsen with sun exposure, and also develop after inflammation from conditions like eczema or contact dermatitis. The color tends to look brown or dark brown and doesn’t change much when you press on the skin or look up.
Vascular
In lighter skin tones, visible blood vessels are often the primary culprit. The darkness looks blue, purple, or pink and comes from dilated or congested veins showing through translucent skin. This was the most common type found in one study of East Asian patients, accounting for about 42% of cases. Anything that increases blood flow or congestion in the area, from allergies to lack of sleep, can make vascular dark circles worse.
Structural (Shadow-Based)
Sometimes what looks like dark pigmentation is actually a shadow. The tear trough, the groove running from the inner corner of your eye toward your cheekbone, can create a visible depression that casts darkness beneath the eye. This hollow forms because the ligaments in this area thin and weaken over time, allowing fat pads to shift and descend. People with prominent cheekbones may have a deeper natural groove in this area even when young, because the gap between bone and skin creates less support for the overlying soft tissue. The telltale sign of structural dark circles is that they look worse in overhead lighting and improve when light hits your face straight on.
Mixed
Most people don’t fit neatly into one category. You might have both visible veins and a deepening tear trough, or pigmentation layered over structural shadows. This is why a single treatment rarely eliminates dark circles completely.
A Simple Way to Check Your Type
You can get a rough idea at home. Gently pinch and lift the skin of your lower eyelid away from the underlying tissue. If the dark color lifts with the skin, it’s likely pigmentation in the skin itself. If the darkness disappears when you pull the skin away, the cause is probably blood pooling beneath the surface, thinned skin revealing vessels, or shadows cast by lost volume underneath.
Allergies and Nasal Congestion
If your dark circles get worse during allergy season, there’s a direct physiological reason. When your nasal passages swell from an allergic reaction, they slow blood flow through the veins around your sinuses. These veins sit close to the surface right beneath your eyes. As blood backs up, the area looks darker and puffier. These are sometimes called “allergic shiners,” and they improve when the underlying congestion clears.
Sleep, Stress, and Lifestyle Factors
Poor sleep doesn’t create dark circles from nothing, but it reliably makes existing ones worse. When you’re sleep-deprived, your skin gets paler, which increases the contrast between your under-eye area and the rest of your face. Blood vessels also dilate, making vascular-type circles more visible. Stress, alcohol, and smoking are all associated with worsening dark circles through similar mechanisms: they affect circulation, skin quality, or both.
UV exposure deserves special mention. Sunlight stimulates melanin production, and the thin under-eye skin is particularly vulnerable. If your dark circles are pigment-based, unprotected sun exposure will deepen them over time.
Iron Deficiency and Anemia
Low iron levels can contribute to dark circles through two pathways. First, iron is essential for producing hemoglobin, the molecule in red blood cells that carries oxygen. When hemoglobin drops, your skin (especially the thin under-eye skin) can look more washed out and bluish because the blood beneath it is less oxygenated. Second, reduced oxygen delivery to tissues may trigger increased melanin production. Since the under-eye area is so thin and sensitive, that extra pigment shows up there first. If your dark circles came on alongside fatigue, shortness of breath, or unusual paleness, it’s worth having your iron levels checked.
Aging and Volume Loss
Age-related dark circles are largely structural. The tear trough ligament, which runs from the inner corner of your eye to the cheekbone, weakens over the years. As it stretches, the fat pads above it descend, creating a visible hollow. Additional weakening of the ligaments around the eye socket deepens this effect. The result is a shadowed groove that makes the area look dark regardless of your actual skin color or blood vessel visibility.
This process is gradual but accelerates noticeably in middle age. It’s why someone who never had dark circles in their 20s can develop prominent ones by their 40s, even without changes in sleep, health, or habits.
Treatment Approaches by Type
Because the causes differ, so do the solutions. What works for pigmented dark circles won’t help structural ones, and vice versa.
For pigment-based circles, topical treatments containing ingredients that suppress melanin production or increase skin cell turnover are the standard starting point. Sun protection is essential. For stubborn cases, certain laser treatments targeting pigment have shown results, typically requiring multiple sessions spaced a couple of weeks apart.
For vascular dark circles, one study tested a topical gel combining vitamin K (which helps with blood clotting and vessel repair), retinol, vitamin C, and vitamin E, applied twice daily for eight weeks. About 47% of the 57 participants saw a meaningful reduction in visible blood pooling. That’s a modest success rate, which reflects the reality that vascular circles are difficult to treat topically. Adequate sleep, managing allergies, and reducing alcohol intake tend to help as well.
For structural or shadow-based circles, topical products do very little because the problem isn’t in the skin itself. Injectable fillers placed in the tear trough can restore lost volume and reduce the shadowed appearance. These typically last several months to over a year. Some people pursue fat grafting or lower eyelid surgery for more lasting correction.
For mixed-type dark circles, a combination approach usually works best. That might mean a retinol product alongside allergy management, or filler combined with a brightening serum. The key is correctly identifying which factors are contributing most and addressing them in order of impact.