Some people can down a few six-packs of beer or a bottle of wine like it was nothing. They'll insist they're not alcoholics. "After all, I'm not stumbling around or slurring my words or blacking out," they'll say. "I merely have a high tolerance. A good metabolism. Solid genetics." In reality, their words show just the opposite. They do have a problem, and it's a big one. Most people who drank that much alcohol would be sick — if they could even get it all down. So if you can drink large quantities of booze and feel just fine afterward, that's actually a bad sign [source: Carise].
Anyone who drinks regularly eventually develops a higher tolerance for booze and its effects. So if you have to drink a lot these days to get a buzz, or if you have to drink more and more over time to feel its effects, you likely have a problem.