What Causes Dark Circles Under the Eyes?

Dark circles are one of the most common things people notice in the mirror, yet they are rarely a single problem with a single cause. The shadow under your eyes can come from pigment, from blood vessels showing through thin skin, from the shape of the bone and fat around the socket, or from everyday habits that make any of these look worse. Understanding which type you have is the first step to choosing sensible skincare and knowing when the answer lies elsewhere.

Why is the skin under the eyes so prone to shadows?

The under-eye area is a special case. The skin here is the thinnest on the face, often around half a millimetre, with very little fat beneath it to pad it out. That means anything under the surface, such as blood vessels or pigment, shows through more readily than it would elsewhere. The area also sits in a natural hollow below the eye socket, so light falls across it in a way that casts shadows. In short, dark circles are usually a combination of what is in the skin, what is under it, and how light hits the shape of your face. Most people have a mix of causes rather than one, and knowing the dominant type helps you set realistic expectations.

What are the pigmentation type (melanin) dark circles?

Pigmentation circles are caused by excess melanin, the same pigment that gives skin its colour. When melanin gathers in the under-eye skin it creates a brown or tan tone that stays fairly consistent whether you are tired or well rested. This type is more common in medium to deep skin tones and often runs in families. It can be driven by genetics, sun exposure, and rubbing or scratching (for example from hay fever or eczema), which prompts the skin to produce more pigment over time. Because the colour lives in the skin itself, it tends not to shift when you press or stretch the area.

• Colour: brown, tan or greyish rather than blue.
• Behaviour: broadly the same morning and night.
• Helped by: daily SPF, gentle brightening ingredients such as vitamin C and niacinamide, and not rubbing the area. These can help brighten the appearance over time but will not remove pigment entirely.

What are vascular (blood vessel) dark circles?

Vascular circles are the classic blue, purple or reddish shadow, and they are the most common type in fair to medium skin tones. They happen because the small blood vessels sitting just beneath thin under-eye skin show through to the surface. Blood that is low in oxygen looks bluish, which is why the area can take on that tired, bruised appearance even when nothing is wrong. This type is closely tied to how you feel on the day: poor sleep, dehydration, alcohol and salty food make the vessels more prominent, so vascular circles often look worse in the morning or after a late night. Congestion and allergies add to it by dilating blood vessels around the eyes.

• Colour: blue, purple or reddish.
• Behaviour: fluctuates, frequently worse when tired, dehydrated or unwell.
• Helped by: hydration, sleep, and topical caffeine, which can temporarily reduce the look of vascular darkness and de-puff the appearance. Our guide on does caffeine eye cream work explains what to expect.

What are structural dark circles (tear troughs and hollowing)?

Structural circles are not really about colour at all; they are about shadow. As we age, the fat pads that cushion the eye area shift and the natural groove between the lower eyelid and cheek, known as the tear trough, becomes more defined. A deeper hollow catches shadow under normal lighting, which reads as a dark circle even though the skin tone may be perfectly even. Some people have prominent tear troughs from a young age purely because of inherited bone and soft-tissue structure. Puffiness plays a part too, as a swollen lower lid casts a shadow directly beneath it. Because the darkness here is a trick of light and shape, topical skincare has limited effect on the shadow itself, though hydrating, plumping formulas can soften the transition and make the area look smoother.

• Colour: a neutral grey shadow rather than a true pigment.
• Behaviour: changes with lighting and head angle; looks better under flat, even light.
• Helped by: make-up, good lighting, and hydrating eye care to smooth the area. Pronounced tear troughs are the type most often addressed by professional treatments if that route interests you.

What lifestyle factors make dark circles look worse?

Whatever your underlying type, a handful of everyday factors act as aggravators. They rarely cause dark circles on their own, but they turn a faint shadow into an obvious one.

• Sleep: too little makes skin paler, which lets underlying vessels and pigment show through more clearly.
• Dehydration: under-eye skin can look dull and sunken, deepening any shadow.
• Screen time and eye strain: long hours leave eyes tired and the area heavier, partly through squinting and rubbing.
• Allergies: hay fever dilates blood vessels and prompts rubbing, both of which darken the area. Persistent symptoms are worth discussing with a pharmacist or your GP.
• Age: skin thins and loses volume over time, so vascular and structural circles become more visible.
• Genetics: the strongest single factor for many people; both pigmentation and tear-trough shape are frequently inherited.
• Sun exposure: ultraviolet light stimulates melanin, so unprotected sun makes pigmentation circles darker. Daily SPF is one of the simplest habits that helps.

How can you tell which type of dark circle you have?

You do not need special equipment to get a good sense of your dominant type. Two quick checks in a mirror, in natural light, usually point you in the right direction.

The gentle stretch test

Very gently stretch the skin sideways at the outer corner of your under-eye, or lightly press the area. If the darkness fades or lightens noticeably, it is likely vascular (you are moving blood away) or pigment-led where the tone spreads out. If the shadow stays put and looks more like a dip catching the light, it is more likely structural, because you are looking at shape rather than colour. Always be gentle here; the skin is delicate and rubbing can make matters worse.

The morning-versus-evening check

Notice when your circles look worst. If they are heaviest after a poor night's sleep, a salty meal or a period of dehydration and ease as the day goes on, that points to a vascular component. If the depth barely changes from morning to night and stays fairly constant regardless of rest, pigmentation or structure is more likely to be driving it.

Look at the colour and the light

Blue or purple suggests vascular. Brown, tan or grey that holds steady suggests pigmentation. A neutral grey shadow that appears or vanishes as you tilt your head or change the lighting suggests a structural tear trough. Many people will recognise a blend, and that is completely normal.

When are dark circles a sign to see your GP?

Dark circles are almost always a cosmetic feature rather than a health concern. Occasionally, though, they can accompany something worth checking. Persistent, pronounced under-eye darkness alongside tiredness can be linked to iron-deficiency anaemia; a bluish or unusually dark look can sometimes relate to thyroid issues; and ongoing puffiness with itching often points to allergies. None of these is diagnosed by appearance alone, so if your circles have changed noticeably, appeared suddenly, or come with other symptoms, see your GP rather than relying on skincare. A cosmetic product cannot address a medical cause.

What can you do once you know your type?

Identifying your dominant type turns guesswork into a plan. Pigmentation responds best to daily sun protection and gentle brightening ingredients used consistently. Vascular circles respond to hydration, better sleep and topical caffeine to reduce the look of darkness and puffiness. Structural circles are usually best softened with hydrating eye care and, where wanted, concealer or a professional consultation. For a step-by-step approach organised by cause, read how to get rid of dark circles, and if you want specific product recommendations our best eye cream and eye serum guide compares options for each type. You can also browse the full eye care collection.

Dark Circle FAQs

What is the most common cause of dark circles under the eyes?

For most people it is a combination, but vascular circles and genetics are the biggest single factors. Thin under-eye skin lets blood vessels show through as a blue or purple shadow, and both pigmentation and tear-trough shape are frequently inherited. Tiredness and dehydration then make whatever is already there look more obvious.

Can lack of sleep really cause dark circles?

Poor sleep does not create dark circles on its own, but it makes existing ones look worse. When you are tired the skin appears paler, which lets underlying blood vessels and pigment show through more clearly, and fluid can gather to create puffiness that casts a shadow. Rest, hydration and cutting late-night salt usually soften the appearance.

How do I know if my dark circles are pigmentation or blood vessels?

Check the colour and do a gentle stretch test in natural light. Brown, tan or grey that stays constant morning and night suggests pigmentation. Blue or purple that lightens when you gently stretch or press the skin, and fluctuates with sleep and hydration, suggests a vascular cause. Many people have a blend of both.

Are dark circles genetic?

Very often, yes. Both the tendency to store extra melanin under the eyes and the shape of the tear trough and bone structure are commonly inherited, which is why dark circles can run in families and appear from a young age. Genetics do not mean nothing helps, but they do shape what realistic results look like.

When should I see a doctor about dark circles?

See your GP if your dark circles have appeared suddenly, worsened noticeably, or come with symptoms such as ongoing tiredness, itching or swelling. Persistent darkness can occasionally accompany anaemia, thyroid issues or allergies. These need proper assessment rather than skincare, since a cosmetic product cannot address an underlying medical cause.