What causes dark circles under your eyes?
The skin around the eyes is particularly thin, around 0.5mm thick as compared to an average of 2mm for the rest of the body. This periorbital skin is translucent, showing the blood vessels (and blood) underneath much more clearly than elsewhere. The actual thickness of this skin varies from person to person and also gets thinner as we age and collagen is depleted.
So why doesn’t that mean you have pink marks under your eyes? Well this depends to some extent on the color of your skin; paler skin tends to filter out all colours except blue, which is why veins below the surface often appear bluish in color. This is exactly what is happening with the circles under your eyes. The blood vessels are what is showing up as the dark bluish marks under your eyes.
But why do my dark circles appear worse sometimes?
So now we know what happens when you get dark marks beneath your eyes, why does this seem to come and go? The main cause of dark circles under the eyes is the blood vessels here becoming a little leaky. Whilst this is generally harmless it does result in blue/black circles under the eyes and can also cause periorbital puffiness (bags) too.
Do allergies cause under-eye dark circles?
So we’ve explained how we get dark marks under our eyes but so far no the factors that can cause them. To a large extent there is a genetic predisposition to getting them due to skin type and colouration but there are also a range of external factors that can cause dark circles. These include dehydration, lack of sleep, alcohol, malnutrition,eczema and yes, allergies.
The way allergies cause dark circles under the eyes is usually indirectly. That is the dark circles are not an actual symptom caused by the allergy but a secondary symptom caused either by you or your bodies response to the allergic reaction. Below we have listed some of the most common ways in which an allergy can cause dark marks under your eyes.
Nasal congestion
This is one of the most common allergic reactions. The lining of the nose becomes irritated and you get the familiar stuffy / runny nose. Nasal congestion may also be responsible for the marks and bags under your eyes. When your nose is blocked the small blood vessels that normally run from your eyes to your nose become enlarged and full of blood. As a result the area under the eyes becomes darker.
If this is a long term problem a possible solution to try is using a saline nasal rinse which may reduce the congestion and your dark circles.
Itchy eyes
Another symptom familiar to allergy sufferers are itchy eyes. Whilst this alone probably isn’t going to cause dark circles your natural response may. Rubbing your eyes, scratching the skin around them or screwing your eyes up may all contribute to the dark smudges under your eyes. That’s because the delicate skin and blood vessels are easily damaged leading to bruising when you rub them.
Lack of sleep
There are times in every allergy sufferer’s life where your sleep gets disturbed. Whether it’s from having a tickly nose or waking up with itchy skin it can all be very disruptive. As we all know not getting enough sleep can lead to dark circles under the eyes – but why?
According to the boffins when your body is low on energy it produces the hormone cortisol which helps break down the body stored fuel. It also has the effect of increasing the amount of blood in your body which in turn dilates and engorges the blood vessels, including those under your eyes. As we discussed above, this is the primary cause of dark circles under the eyes.
As you can see there are some concrete reasons why dark rings can be yet another symptom of allergy. How affected you are by this is largely down to genetic factors such as the color and thickness of your skin and how easily you bruise. However, avoiding rubbing your eyes and getting plenty of sleep can certainly help with reducing the dark marks under your eyes.