Usually it means it wants drugs or some stimulant that you eat, drink, smoke or inject that will give immediate satisfaction

If you are ever in this situation .... go for a walk, run, exercise or lift weights ... the dopamine hit from the effort will immediately satisfy whatever it is the brain is feeling and also make you forget about other things for a while. Physical activity immediately relieves those bits of stress.

Because if you don't ... you're on the path to wanting to satisfy these cravings with a pill or drug ... either legal or illegal and you're on your way to more problems.