Withdrawal from nicotine, an addictive drug found in tobacco, is characterized by symptoms that include headaches, anxiety, nausea, and cravings for more tobacco. Nicotine creates a chemical dependency so that the body develops a need for a certain level of nicotine at all times. Unless that level is maintained -- by smoking or chewing tobacco -- your body will begin to go through withdrawal.
For tobacco users trying to quit, symptoms of withdrawal from nicotine are unpleasant and stressful -- but they are temporary. Most withdrawal symptoms peak 48 hours after you quit and are completely gone in six months. But after that, you may still have to deal with the fact that many people trying to quit smoking find themselves eating more and gaining weight in the process.