Smoking a cigarette for the first time ever is often toxic enough to make some people vomit, Kids Health says. Other early effects include coughing, a burning sensation and an overall sickly feeling. Those who make smoking a habit learn about the health dangers, the smelly side effects and the high cost. Despite a host of negatives, people still get addicted to smoking.
Nicotine is the drug in cigarettes, and all tobacco products, that make smoking so addictive. Nicotine is so powerful that the scant 1 to 2 mg a smoker inhales from each cigarette is enough to turn into an addiction, notes the National Institute on Drug Abuse (NIDA). When someone inhales a cigarette, the nicotine shoots into the lungs, is quickly absorbed into the blood, and is hitting the brain about eight seconds after the puff. Overall, a single cigarette has about 10 mg of the drug, but some of it goes up in smoke and is not inhaled.
Once nicotine gets into the brain, it causes brain neurons to create dopamine, a neurotransmitter that emits a feeling of pleasure, NIDA explains. Dopamine naturally occurs when people are in situations that make them feel good, and nicotine kicks the dopamine creation into overdrive. Smoking a cigarette, therefore, can give someone an immediate pleasurable reaction and, as people want more of a good thing, the cycle of smoking begins. Nicotine hits the brain and causes pleasure quite quickly, and its effects wear off just as rapidly.
As with many drugs, the body builds up a tolerance to nicotine, NIDA points out. Smokers start to need more nicotine to get the same effect. They usually end up smoking more often to get that same nicotine high. Nicotine tolerance builds up quickly over the course of the day during continuous smoking. Long stretches without a cigarette, like while sleeping, bring the tolerance back down.
Physical symptoms of nicotine withdrawal are most severe the first few days without a cigarette, NIDA says. People experiencing nicotine withdrawal are often irritable, have a hard time sleeping and difficulty paying attention or thinking clearly. They also often end up with a huge appetite and intense longing, or craving, for a cigarette. The physical symptoms of nicotine withdrawal eventually lessen over time, frequently disappearing altogether after several weeks without nicotine. Cravings for a cigarette, however, can last a lifetime.
Even when nicotine withdrawal subsides, some former smokers have intense cravings for a cigarette, NIDA notes. These cravings can come from seeing or smelling a cigarette or are often triggered by some of the psychological aspects of smoking. These include hanging around people the smoker used to smoke with or places where he used to smoke. Some people continue to crave a cigarette at times when they used to always smoke one, like right after eating or while drinking alcohol. The entire ritual of smoking, from lighting it to inhaling the last puff, is another intense longing that often lingers. Cravings are one of the top reasons people fail at quitting smoking.