The effects of smoking on the respiratory and cardiovascular systems are well known, but there is another reason to consider quitting: your sleep health. Not only is smoking associated with getting less sleep, but it also is responsible for changing your sleep pattern so that even a full night in bed does not feel restful. Smoking tobacco prevents a full night’s sleep in several ways. Over the long term, it can also lead to a serious sleep disorder known as sleep apnea.
Reduced Deep Sleep
The most dramatic effect of smoking on sleep is a reduction in the time spent in deep sleep, which is known for creating that “restorative” feeling people have when they wake up in the morning. In 2008, the journal "Chest" reported that chronic smokers spend more time in light sleep, especially in the early parts of the night. The culprit is nicotine, which has a stimulating effect on the nervous system. Ironically, as nicotine is reduced in the bloodstream throughout the night, withdrawal symptoms increase. Symptoms include restlessness and insomnia.
Increased Sleep Fragmentation
Because deep sleep is reduced in chronic smokers, the time spent in bed does not indicate a “good night’s sleep.” This is partially due to less deep sleep, but also to sleep fragmentation, or the increased likelihood of awakening in the night. Dr. Ron Kramer of the American Academy of Sleep Medicine reports that, in 2006, the CDC completed a door-to-door survey of 87,000 individuals about their sleep health. Researchers found that smokers are heavily represented in the group of people who get less than six hours sleep, and also among those who get more than nine hours of sleep. Too much time in bed is often an indication that the restorative benefits of sleep are not being met. While the cause is not clear, the pattern is that smokers as a whole are not well-rested.
High Risk for Sleep Apnea
Smoking is also an independent risk factor for a dangerous sleep disorder known as obstructive sleep apnea (OSA). According to the Mayo Clinic, smokers are three times more likely to have OSA than people who have never smoked. During OSA, airways are constricted or clogged, preventing enough oxygen from reaching the brain during sleep. Extraordinarily loud snoring and waking up and gasping for breath are two common symptoms of OSA, which, if left untreated, can lead to pulmonary hypertension, heart failure and early death. Smoking increases the risk for OSA because the habit irritates the throat lining and leads to nighttime congestion.
Quitting and Sleep Health
The good news is that quitting smoking can immediately improve sleep health. This has been known for decades. In a well-documented and influential 1980 article in the journal "Science," researchers found that sleep patterns improved considerably after subjects abstained from cigarettes. This is most likely due to the harmful effects of nicotine on the sleep-wake cycle. Once nicotine is out of your system, sleep improves and the restorative benefits of sleep return.