Dark circles under the eyes are usually more noticeable when you're tired. Other lifestyle factors that may contribute to dark circles under the eyes are smoking, drinking too much alcohol and stress.

Sometimes, what looks like dark circles may be shadows cast by puffy eyelids or hollows under the eyes that develop with aging.

Some of the most common causes of dark circles under the eyes are:

1. Atopic dermatitis (eczema)
2. Contact dermatitis
3. Fatigue
4. Genetics
5. Rubbing or scratching your eyes
6. Skin changes that happen with aging
7. Changes in skin color. These changes may be from melasma or post-inflammatory hyperpigmentation, both of which are more common in people with brown or Black skin.
8. Sun exposure