Withdrawal is the physical and emotional symptoms that occur after quitting. These symptoms include irritability, insomnia, tiredness, sore throat, dizziness, and trouble concentrating. There are both physical and psychological causes for withdrawal. The physical causes relate to the fact that the neurochemistry of smokers' brains changes in the presence of nicotine. Nicotine enhances the release of a chemical messenger called dopamine, which produces feelings of pleasure and satisfaction. Normally, the body uses dopamine as part of a reward system that encourages behaviors essential for survival, such as eating. However, sustained smoking causes the body to depend on nicotine for the release of normal amounts of dopamine. When smokers quit, the body once again has to recalibrate the regulation of dopamine and other neurotransmitters that control mood. In the short term, for quitting smokers, that means dopamine levels are out of balance, a situation that leads to irritation and other withdrawal symptoms.

Usually, symptoms of nicotine withdrawal begin rapidly and peak within one to three days. Because of this rapid onset of withdrawal symptoms, only about 30 percent of people who try to quit smoking remain tobacco free for even two days. Withdrawal symptoms generally last three to four weeks, but some smokers have withdrawal symptoms that last more than a month. Some people have strong cravings for tobacco that last for months, even though the physical addiction to nicotine is long past. These cravings often occur in social settings in which the person formerly smoked, such as at a bar or party, or after sex. Researchers believe that much of this extended craving is psychological.

You can overcome withdrawal symptoms by trying the following:

Irritability. Take a deep breath; exercise; picture in your mind a relaxing event or place.

Tiredness. Take it easy; take a nap; go to bed early.

Insomnia. Avoid caffeine after 4 p.m.; try relaxation techniques.

Sore throat. Drink plenty of liquids; use cough drops; or chew gum.

Dizziness. Use extra caution when driving or operating machinery. Rest.

Trouble concentrating. Avoid demanding jobs, if possible, during the first few weeks.