Why do we have cravings?

I crave weed , some of my other friends get mad at me when I do it , So I really need to know ASAP!!! Any suggestions?!

My girlfriend is in a seriously bad mood at the moment. I think it's because she's trying to quit smoking (it could be that s...

Lately when I am tired I have been craving chocolate OR bread and butter! I have NOOO idea why and it drives me nuts and make...

What weird cravings did you all get during pregnancy? And how far gone were you? I'm interested! As I've started to crave mel...

I just had s*x like 20 days ago and no roadblocks I should be okay like I was just craving an apple I HATE healthy food! cou...

Usually for a week before I get my period, I Get real bad cramps,Bad Headaches,and even Worse food Cravings. I eat so much it...

I have drank alcohol sometimes.. when I dont have it for a long time I crave it. is that bad??

Ok so my fiance and I are trying to have a baby but no luck and all of a sudden the last few weeks I get the craving for stuf...

I've been having really BAD, crazy cravings and I've been prego for only 3 weeks. Is this normal, or whats going on?

I havn't smoked in a long time, but I'm really stressed out, and I need a cigarette real bad. Any suggestions to fend off the...