Dark circles are described as round, uniformly dark pigmented areas under the eyes. Though being tired may not cause dark circles, stress and fatigue may worsen it. The skin around our eyes is thinner than in other areas and have less fat and collagen. The large veins close to the areas under the eyes show through the thin skin making the skin look darker.
Causes
There are quite a few other reasons like –
Heredity
Dark circles under eyes can run in families and can be inherited. With inherited pale skin and thin under eye- skin, you can be more susceptible to DC. Having high cheek bones and deep-set eyes can create hollow-eyed look as well.
Sun exposure
Being exposed to sun especially during peak hours (11 am to 4 pm) triggers more melanin production. Sensitive eye areas may get dehydrated with dark circles forming under them and appearance of wrinkles.
Aging
As we age,there is loss of fat below the eyes and the skin especially under our eyes get thinner and so veins/capillaries underneath are closer to surface and become more visible. This bluish tint looks like black dark circles. Sometimes thin capillaries break and cause leakage which turn blue.
Sleep
Excess and insufficient sleep both can cause dark circles. Especially if you sleep with head at the same level and not elevated, fluid may get collected under the eyelids because of gravity and puffy eyes cast shadows that look like dark circles.
Hormonal imbalance
Fluid retention due to Hormonal imbalance (Pregnancy, menstruation, hypothyroidism)
Allergies
Skin conditions like eczema, hay fever and allergies can cause itchiness and frequently rubbing the eyes repeatedly can cause dark circles in some people.
Sinus problems
Chronically infected sinuses dilate the veins around the eye areas and this causes puffiness and swelling of the area creating dark circles.
Lack of nutrition & Dehydration
Not taking balanced nutritious diet and dehydration can cause dark circle formation. Deficiency of iron, vitamins C and K can cause dark circles.
Kidney/intestinal problems
Some healthcare concerns like kidney disease can cause dark circles.
Lifestyle issues
Smoking, excessive alcohol, stress – both physical and mental – can be other causes for dark circles.
Makeup – Repeated application of dark kohl eyeliner
Prognosis
Dark circles (DC) can appear under your eyes even when you have had perfectly good sleep, rested and in no way fatigued. What exactly causes dark cycles under the eyes is not known. Puffy eyes and hollow areas under eyes causing dark circles can be managed by self-care tips and a variety of measures like home remedies, make-up for camouflaging and procedures like dermal fillers, chemical peeling, laser etc.
