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 subside over the next 3 to 4 weeks. 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.