Addiction to smoking can be conditionally divided into several stages.

The first stage is occasional smoking

They smoke in certain situations, often “for company,” consuming 1–3 cigarettes a day, 1–2 times a week. At this stage, there is no craving for tobacco, and no physical dependence on nicotine. The consequences of nicotine use at this stage may include occasional disturbances in the cardiovascular system and autonomic nervous system, which are functional in nature and quickly subside once smoking is stopped.

The second stage is systematic smoking

The number of cigarettes smoked ranges from 3 to 7 per day. The craving intensifies, driven not only by psychological but also by physical dependence. There emerges a desire not only to experience pleasure but also a need to relieve discomfort and to relax.

The third stage is pronounced chronic intoxication

The craving is defined by both psychological and physical dependence. The smoker smokes from 10 to 25 cigarettes a day. The urge to smoke intensifies, and abstaining from it leads to the appearance of withdrawal syndrome. In the psychological sphere, increased irritability is observed. Somatic disorders are common, particularly in the respiratory system and gastrointestinal tract, as well as a decrease in sexual function.

The fourth stage is severe chronic intoxication

The craving for tobacco smoking is sharply pronounced. Typically, 30-60 cigarettes are smoked per day. Smoking occurs both during the day and at night. The withdrawal syndrome is strongly expressed. There is pathology in the respiratory system, including chronic bronchitis, emphysema, heart failure, and coronary artery disease. Irreversible changes occur in many organs and systems of the body.