Could be lack of sleep or a cortisol deficiency.

If you are very, very thin, have no energy, tend to run on adrenaline, see yourself as a victim, then could be cortisol.

The problem could be connected also with liver suffering.

Another possible cause is the position during sleep.

Sleeping belly up possibly with a pillow that keeps your head a bit raised helps draining eye circles.

Sleeping face down does the opposite.