How Smoking Affects Sleep
If you’re a smoker, you probably already know that smoking has many health risks. However, what you might not know is that smoking can profoundly affect your sleep. Despite the fact that many smokers view smoking as a sleep aid, data shows that it actually tends to disturb rather than support healthy sleep.
There are many factors that lead to smoking-related sleep disturbances, and each person will experience them differently. For one, nicotine is a stimulant: in terms of getting to sleep, smoking a cigarette before bed is the equivalent of drinking a cup of coffee before bed. While some people may be able to drink a cup of coffee before bed and fall asleep just fine, most people would find it difficult. Another thing about smoking that affects sleep is nicotine withdrawal during the night, which can cause restlessness and frequent awakening. Nicotine also alters your natural circadian rhythms, which makes it more difficult to achieve fully restorative sleep. Finally, smoking-related respiratory issues can disrupt sleep even further, and even cause chronic sleep deprivation.
What is Nicotine?
Nicotine is an alkaloid (or, an organic compound that contains nitrogen), which is produced naturally by plants in the nightshade family.
Nicotine functions in several ways in the brain and the body, as both a stimulant and a mild euphoriant. When nicotine first enters the body, it stimulates the adrenal glands to produce epinephrine (aka adrenaline) and thereby causes an increase in blood pressure, respiration, and heart rate. It also activates certain reward centers in the brain, called “dopaminergic neurons”, which release dopamine. Located in a region of the brain called the ventral tegmental area (or, VTA), these neurons have evolved to reward positive behaviors with pleasurable feelings, such as the satisfaction you get from drinking a cup of water when you’re dehydrated.
When nicotine enters the brain, it attaches to the dopaminergic neurons and causes them to flood areas of the brain with dopamine. This produces a feeling of pleasure and the quick kick of euphoria that smokers often experience, and also predisposes a person to repeat the behavior that led to the pleasure. This is one cause of nicotine addiction.
Another cause of nicotine addiction is the speed with which it is processed by the body. Specifically, nicotine is absorbed very rapidly into the blood and delivered quickly into the brain, causing nicotine levels to peak within 10 seconds. This both offers a near-immediate pleasure response and reduces the length of the “high”, which often causes the smoker to continue smoking in order to prolong or repeat that pleasure.
Repeated exposure to nicotine alters the brain’s sensitivity to dopamine and can lead to changes in other brain circuits that deal with stress and self-control. This can cause a person to rely on nicotine to maintain base levels of dopamine and other neurochemicals. This reliance on nicotine is referred to as “nicotine dependence.” Once a person is dependent on nicotine, failure to administer the drug can lead to withdrawal.
Nicotine Withdrawal: Challenges and Symptoms
Nicotine withdrawal symptoms vary based on how heavily dependent a person is on nicotine, and how sensitive their body is to withdrawal. However, common symptoms include:
- Depression and anxiety
- Problems with cognitive functioning
- Appetite issues
- Sleep problems
- Aches and pains
For most people, physical withdrawal symptoms peak within the first few days of their last nicotine dosage, and usually subside within a few weeks. Smokers can use nicotine replacement therapies, such as gum, patches, and medications, to wean themselves off the drug and help with the physiological aspects of withdrawal.
However, there are also social and behavioral factors that can intensify and/or prolong withdrawal. Learning processes in the brain associate the behaviors around cigarette smoking (such as the smell or sight of a cigarette, or the rituals around lighting a cigarette) with nicotine-induced pleasure surges, which can cause these behaviors or sensory experiences to trigger cravings. People who quit smoking are encouraged to avoid these triggers, and in some cases to seek behavioral therapies to help cope when the triggers are encountered.
Though nicotine is not the only harmful chemical in cigarettes, it is very addictive, and also has been shown to have its own health risks. A recent review of medical literature on nicotine showed that it poses an increased risk of cardiovascular, respiratory, and gastrointestinal disorders, as well as a decreased immune response, and negative impacts on reproductive health. It also showed that nicotine affects many of the various mechanisms which lead to cancer, including cell proliferation, apoptosis (cell death), DNA mutation, and oxidative stress (an imbalance between free radicals and antioxidants in the body). In cancer patients, it affects tumor proliferation and metastasis and causes resistance to chemo and radiotherapeutic agents.
Quitting nicotine isn’t easy, over 85% of smokers relapse after their first attempt to quit. However, with the right support network and withdrawal coping tools, quitting is possible.
Nicotine and Insomnia
The effects of nicotine are one of the main reasons that smoking affects sleep. Specifically, three effects of nicotine cause disturbed sleep:
- Overnight nicotine withdrawal, which can cause disturbed sleep, frequent awakening, and restlessness;
- The stimulant effects of nicotine, which can cause insomnia and difficulty getting to sleep; and,
- The changes nicotine makes to the body’s natural circadian rhythm, which can reduce and even fully disrupt the body’s ability to obtain restorative sleep.
Overnight Nicotine Withdrawal
Overnight nicotine withdrawal is a phenomenon experienced by many smokers, especially heavy smokers. During the day, the body of a smoker is accustomed to craving nicotine and then getting nicotine in regular intervals in the form of smoking. However, during sleep, it is impossible to deliver nicotine when the body craves it. Therefore, the body starts to feel withdrawal symptoms, which can start as early as 2 hours after the last cigarette smoked.
Overnight nicotine withdrawal is one of the ways in which smoking disturbs sleep. It can cause trouble falling asleep, trouble staying asleep, frequent awakening, tossing and turning, and general restlessness. In addition, overnight nicotine withdrawal only furthers the sleep disturbances that come from earlier stages of sleep, when high levels of nicotine, which is a stimulant, are still in the blood.
Nicotine Levels Across Products
Different sources of nicotine can cause different levels of overnight nicotine withdrawal, depending on how much nicotine is in the product, and how often it is used.
As you can see, cigarettes have 1.1mg to 1.8mg per cigarette, which is 22mg to 36mg/pack. However, a study from the CDC has found that smokers of lower-nicotine cigarettes tend to ingest as much if not more nicotine than smokers of higher-nicotine cigarettes because they smoke more frequently and inhale more deeply in order to compensate for the lower nicotine yield. Similarly, while some people feel that self-rolled cigarettes are safer or have less nicotine than pre-rolled cigarettes, studies have found that self-rolling smokers smoke more intensively, inhale more smoke per cigarette, and take longer and more frequent puffs.
Meanwhile, many people see social, situational smoking, such as hookah-smoking, as less harmful than smoking cigarettes. However, as the chart shows, in one 40-60 minute sitting, a hookah will put out approximately one pack of cigarettes worth of nicotine.
Another thing to consider is vaping and e-cigarettes. Though smokeless cigarettes are often presented as being safer than traditional cigarettes, since they do cut out some of the harmful chemicals in traditional cigarettes, they deliver nicotine at least the same, and often far higher levels than traditional cigarettes. For instance, one JUUL pod contains as much nicotine as approximately 20 cigarettes.
Circadian Rhythm Changes
Smoking causes changes to the body’s natural circadian rhythm. This is because nicotine alters the expression of certain genes in both the lungs and the brain that regulate the sleep-wake cycle. A 2014 study found that cigarette smoke affected these “clock genes” by producing parallel inflammation in the lungs and depressed levels of locomotor activity in the brain. It also found that smoking decreased the production of the SIRTUIN1 molecule, which in turn altered the levels of the clock protein BMAL1 in both lung and brain tissues, causing a disturbance in the sleep cycle/molecular clock.
As a result of these changes, smokers experience a disruption to their sleep architecture, meaning the cycling between sleep stages that results in restful, restorative sleep.
A person experiencing healthy sleep generally cycles through four stages: two stages of “light sleep”, one stage of “deep sleep”, and one stage of REM (or rapid eye movement). Each cycle takes around 90 to 110 minutes, with each individual stage taking between 5 and 15 minutes. The later the cycle is in the course of the sleep, the longer the REM stage lasts.
Both long-term and short-term smoking disrupts those cycles. This means that smokers spend less time in slow-wave deep sleep and REM sleep, both of which are crucial for restorative rest. It also causes smokers to have shorter sleep periods overall, by an average of 33 minutes. It is probably due to this disruption that smokers are 4 times more likely than nonsmokers to report feeling unrefreshed after sleep.
The repercussions of disrupting your circadian rhythms reach beyond the bedroom: consistent poor sleep can lead to daytime fatigue, cognitive impairment, irritability, depression, and anxiety.
Increased Risk of Sleep Apnea
Obstructive sleep apnea is a condition in which breathing repeatedly stops and starts during sleep. It is caused by a blockage of the airways. This blockage can occur in one of two ways.
One way has to do with the muscles in the back of the throat, which support the soft palate, the uvula (the piece of tissue that hangs from the soft palate), the tonsils, the walls of the throat, and the tongue. If these muscles relax too much during sleep, it can lead to blocked airways. The other way has to do with excessive tissue around the airways that restrict breathing during the night. This can be caused by issues like obesity and jaw alignment problems.
In either case, because of airway blockages, people with sleep apnea regularly do not get enough oxygen as they sleep. This causes the level of oxygen in the blood to drop, which is sensed by the brain. The brain then briefly wakes the person up from sleep so that they can get more oxygen. This generally presents as a gasp or a choking sound.
Often, the awakening is so brief that the person experiencing it does not remember it happening. However, these awakenings can go on all night, sometimes over 30 times an hour, which prevents a person from reaching the most restful and restorative levels of sleep. People with sleep apnea often wake up with a dry mouth and/or a headache, and can experience daytime fatigue, difficulty paying attention, and irritability.
Obstructive sleep apnea can have serious medical complications. It can lead to high blood pressure and general cardiovascular problems, increases your risk of developing insulin resistance and diabetes, liver problems, and complications with medications and surgery.
Smokers are up to 2.5 times more likely to suffer from obstructive sleep apnea. This is likely because inhaling smoke irritates the tissues in the nose and throat, which causes swelling that restricts airflow.
Frequently Asked Questions About Smoking and Sleep
Learn More About Smoking and Sleep
Any smoker will tell you that quitting smoking isn’t easy. It’s totally understandable to feel overwhelmed, frustrated, and even scared when facing the prospect of giving up smoking, which may have been a part of your life for many years. However, you do not have to do it alone.
Each year, around 1.3 million smokers quit. Since 1965, more than 40 percent of all adults who have ever smoked have quit. This is due largely in part to the many smoking cessation tools, resources, and support networks in place to help people who want to quit stop smoking for good. Here are 10 excellent resources for those who want to kick their smoking habit to the curb.
- SmokeFree.Gov: This governmentally funded smoking cessation hub has tons of tools and information sources. Go here to find the QuitStart app, which is a free, personalized mobile app with tips, craving-fighting tools, inspiration, and other support sources, and sign up for Smoke Free Txt, daily text messages with encouragement and advice. You can also create a quit plan, and connect with other people going through the quitting process through their social media platforms.
- 1-800-QUITNOW: A toll-free hotline where you can chat with an expert about quitting. Call this number if you’re even considering quitting: it always helps to have a person on the other end of the line to talk to. For Spanish speakers, call 1-855-DEJELO-YA for the same free service, only in Spanish.
- Tips from Former Smokers: Though it may seem a little scary, this site has first-hand advice from former smokers, including multimedia testimonials. They also offer CDC-endorsed resources and tools for smoking cessation.
- Smoke-Free Teen: Catered specifically to teenagers and young adults who are struggling with smoking, this site has information, testimonials, tips, apps, and a designated call line and chat line where you can talk to an expert.
- FDA-Approved Smoking Cessation Products: This is a basic, 101 explanation of all the smoking cessation products on the market that are approved by the FDA. Learn about Nicotine Replacement Therapies (NRT) like lozenges, patches, and gum, as well as prescription cessation medications like Chantix and Zyban.
- Help! I Want to Quit Smoking!: This multifaceted resource was put together by the American Heart Association. It includes quitlines in many different languages (including Chinese, Korean, Vietnamese, and TTY for the deaf and hard of hearing), information, tips, and online communities.
- Nicotine Anonymous (NicA): A 12-step program to help those who want to quit smoking. They offer a database of face-to-face meetings all over the country, as well as online meetings, Skype meetings, pen-pal programs, and kits to start your own meeting.
- Smoking Cessation Leadership Center: A comprehensive body of information and collection of resources from the University of California, San Francisco, from an organization that is leading smoking cessation outreach and advocacy programs around the country.
- Become An Ex: The Mayo Clinic’s free network of support, which includes a customized quit plan, encouraging text messages, guides and tools, expert advice and tips, and an active community of ex tobacco users.
- R/Stopsmoking: A subreddit with over 91,000 members about quitting smoking, by and for people who have been there. If you don’t have a Reddit account, it’s free to sign up, and for those quitting smoking, it’s worth it just for this subreddit.