It's a classic image - wake up, light up.
Within 5 minutes of waking up in the morning, 14 % of smokers light up. Over 50% smoke within 30 minutes of waking. [3] Why? Because you can't smoke and sleep at the same time!
The average smoker consumes ~ 15 cigarettes per day, regularly spaced throughout their waking hours so that nicotine is constantly present in the their blood.[2] But, although an alarming number of house fires are due to smokers falling asleep with a lit cigarette, smoking while actually asleep is not possible.
Because nicotine is not a natural part of the body’s chemistry, the liver is constantly removing it from the blood and destroying it. While awake, another cigarette will replenish the nicotine. But while asleep, the liver gets ahead. For an addicted body, going without a fresh dose of nicotine for eight hours during sleep is enough to trigger withdrawal symptoms in the morning.
Many smokers describe their morning cigarette as the best smoke of the day. From the body’s point of view, the day's first smoke is giving the body back the accustomed level of nicotine.
According to Dr David Kessler, in a speech to the House Subcommittee on Health and the Environment. "When a smoker sleeps, blood levels of nicotine decrease significantly. But the smoker doesn't need to be an expert on the concept of nicotine blood levels to know full well what that means." He goes on to describe that how soon an addict uses a drug after they wake up is a meaningful measure of how addicted they are.
The body’s addiction to nicotine is due to nicotine's ability to mimic a very important chemical in the body called Acetylcholine. The brain uses Acetycholine to send messages from one cell to another. When nicotine is present the brain senses that there are too many Acetlycholine type messages. Over time the brain gets used to having the nicotine around and only responds to the Acetlycholine messages when they are accompanied by nicotine. At this point, the brain prefers to work with a constant level of nicotine in the blood. As smokers sleep, the level of nicotine in the blood drops. In response, the body shuts down its Acetlycholine messenger system, producing the withdrawal symptoms of the increased anxiety, restlessness and cravings for nicotine. By the morning, smokers must now wake up and greet the day with a nicotine fix.
For more information see Brain, and Nicotine.
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