What causes dark circles under the eyes?

For years cosmetics companies have sold products to prevent or conceal the dark circles many people get under their eyes. These “bags”, or periorbital dark circles to give them their proper name, are often attributed to tiredness, lack of sleep or a poor diet. But for a lot of people there’s a different reason for their presence.

The skin below and around our eyelids is only 0.5mm thick, compared to an average of 2mm thick on the rest of our bodies. This means that the blood vessels that lie just beneath the skin are more clearly visible, as is the blood they contain. This makes the skin appear to be a darker shade than on the rest of the face and body; it’s also why bruises around the eyes are more obvious than those elsewhere.

So why do some people have darker circles than others? Sometimes it’s genetic, running in families, and sometimes it’s just chance. A diet that’s too high in salt can cause puffiness around the eyes, which exacerbates the appearance of dark circles. Skin gets thinner as the person gets older, which is why elderly people often have particularly pronounced circles, and the increase in blood flow in pregnant women is also a contributing factor to theirs.

Interestingly, tiredness can cause the circles under our eyes to darken and there’s a reason for this. When we’re tired our bodies produce the chemical cortisol to increase our energy levels, and this actually increases the volume of blood. As with pregnant women, this increase in volume makes the blood vessels below our eyes darken and seem more obvious.

So while concealing dark circles is possible with the use of cosmetics, there’s very little you can do to prevent them appearing in the first place. Sorry!