Nicotine withdrawal is associated with physical symptoms that are often associated with smoking relapse. Withdrawal symptoms are most intense in the first week of smoking cessation and usually last for 2–4 weeks. Common withdrawal symptoms include:

  • Mood changes, including agitation, aggression, depression and anxiety;
  • Restlessness;
  • Poor concentration;
  • Increased appetite;
  • Disturbed sleep;
  • Decreased heart rate; and
  • Decreased levels of adrenaline and cortisol.