Dark circles under the eyes usually come from a mix of skin pigmentation, visible blood vessels, and shadows from the eye structure, most often influenced by genetics, aging, fatigue, and lifestyle factors. They are common and usually not dangerous, but sometimes point to issues like allergies, eczema, or anemia.

What dark circles actually are

Dark circles are areas of darker skin or shadowing under the eyes, often bluish, purplish, or brownish. They can come from extra pigment in the skin, blood vessels showing through thin skin, or simply the shape of the eye socket casting a shadow.

Main medical and skin causes

  • Pigmentation changes : Extra melanin in the under‑eye skin (hyperpigmentation), often more visible in medium to darker skin tones; this can be genetic, sun‑induced, or post‑inflammatory after dermatitis. Conditions like melasma or post‑inflammatory hyperpigmentation can deepen the color.
  • Eczema or contact dermatitis: Atopic dermatitis and allergic/contact dermatitis around the eyes can cause inflammation and rubbing, leading to darkening over time.
  • Visible blood vessels: Thin under‑eye skin and superficial veins can make the area look blue or purple, even if the skin pigment is normal.
  • Periorbital edema: Mild puffiness or fluid retention can create a shadow and make the area look darker.

Lifestyle and everyday triggers

  • Fatigue and lack of sleep : Poor sleep makes skin look dull, can cause mild under‑eye puffiness, and makes veins and shadows more obvious.
  • Eyestrain and screen time: Staring at screens can strain the eyes and dilate blood vessels around them, accentuating dark circles.
  • Dehydration: When not well hydrated, the under‑eye skin looks dull and eyes appear more sunken, deepening shadows.
  • Sun exposure: UV light boosts melanin production and can leave long‑term darkening under the eyes.
  • Smoking and poor diet: Smoking, lack of exercise, and nutrient deficiencies (like iron, vitamin C, vitamin E) can impair circulation and skin quality, making dark circles more visible.

Genetics, age, and health conditions

  • Genetics : Many people inherit naturally thin under‑eye skin, deep‑set eyes, or a tendency to pigment more in that area, so dark circles show up even with good sleep.
  • Aging: With age, skin thins and fat under the eyes decreases, so blood vessels and bone structure show through more clearly.
  • Allergies and rubbing: Seasonal allergies and chronic eye rubbing both increase inflammation and pigment changes around the eyes.
  • Anemia and systemic issues: Iron‑deficiency anemia and some thyroid conditions can make skin paler and circulation poorer, so dark vessels and shadows stand out.

When to worry and what to consider

Most dark circles are a cosmetic issue, but a doctor or dermatologist should be consulted if:

  • They appear suddenly or worsen quickly without clear cause.
  • They come with other symptoms like severe fatigue, dizziness, skin rashes, or eye pain, which might signal anemia, allergies, or other health problems.

Information gathered from public forums or data available on the internet and portrayed here.