Mark Twain said, “Quitting smoking is easy. I’ve done it a thousand times.” Maybe you’ve tried to quit, too. Why is quitting and staying quit hard for so many people? The answer is mainly nicotine.
Nicotine is a drug found naturally in tobacco, which is as addictive as heroin or cocaine. Over time, a person becomes physically dependent on and emotionally addicted to nicotine. This physical dependence causes unpleasant withdrawal symptoms when you try to quit. The emotional and mental dependence (addiction) make it hard to stay away from nicotine after you quit. Studies have shown that to quit and stay quit, smokers must deal with both the physical and mental dependence.
How nicotine gets in, where it goes, and how long it stays
When you inhale smoke, nicotine is carried deep into your lungs. There it’s quickly absorbed into the bloodstream and carried, along with the carbon monoxide and other toxins, to every part of your body. In fact, nicotine inhaled in cigarette smoke reaches the brain faster than drugs that enter the body through a vein (intravenously or IV).
Nicotine affects many parts of your body, including your heart and blood vessels, your hormones, the way your body uses food (your metabolism), and your brain. Nicotine can be found in breast milk and even in the cervical mucus of female smokers. During pregnancy, nicotine crosses the placenta and has been found in amniotic fluid and the umbilical cord blood of newborn infants.
Different factors affect how long it takes the body to remove nicotine and its by-products. In most cases, regular smokers will still have nicotine and/or its by-products, such as cotinine, in their bodies for about 3 to 4 days after stopping.
How nicotine hooks smokers
Nicotine causes pleasant feelings and distracts the smoker from unpleasant feelings. This makes the smoker want to smoke again. Nicotine also acts as a kind of depressant by interfering with the flow of information between nerve cells. Smokers tend to smoke more cigarettes as the nervous system adapts to nicotine. This, in turn, increases the amount of nicotine in the smoker’s blood.
Over time, the smoker develops a tolerance to nicotine. Tolerance means that it takes more nicotine to get the same effect that the smoker used to get from smaller amounts. This leads to an increase in smoking. At some point, the smoker reaches a certain nicotine level and then keeps smoking to keep the level of nicotine within a comfortable range.
When a person finishes a cigarette, the nicotine level in the body starts to drop, going lower and lower. The pleasant feelings wear off, and the smoker notices wanting a smoke. If smoking is postponed, the smoker may start to feel irritated and edgy. Usually it doesn’t reach the point of serious withdrawal symptoms, but the smoker gets more uncomfortable over time. When the person smokes a cigarette, the unpleasant feelings fade, and the cycle continues.
Nicotine withdrawal symptoms can lead quitters back to smoking
When smokers try to cut back or quit, the lack of nicotine leads to withdrawal symptoms. Withdrawal is both physical and mental. Physically, the body reacts to the absence of nicotine. Mentally, the smoker is faced with giving up a habit, which calls for a major change in behavior. Emotionally, the smoker may feel like they’ve lost their best friend. All of these factors must be addressed for the quitting process to work.
Those who have smoked regularly for a few weeks or longer will have withdrawal symptoms if they suddenly stop using tobacco or greatly reduce the amount they smoke. Symptoms usually start within a few hours of the last cigarette and peak about 2 to 3 days later when most of the nicotine and its by-products are out of the body. Withdrawal symptoms can last for a few days to up to several weeks. They will get better every day that you stay smoke-free.
Withdrawal symptoms can include any of the following:
- Dizziness (which may last 1 to 2 days after quitting)
- Feelings of frustration, impatience, and anger
- Sleep disturbances, including having trouble falling asleep and staying asleep, and having bad dreams or even nightmares
- Trouble concentrating
- Restlessness or boredom
- Increased appetite
- Weight gain
- Constipation and gas
- Cough, dry mouth, sore throat, and nasal drip
- Chest tightness
- Slower heart rate
These symptoms can make the smoker start smoking again to boost blood levels of nicotine until the symptoms go away. (For information on coping with withdrawal, see the section called “Dealing with smoking withdrawal.”)
Other substances in cigarette smoke
There is some evidence that other chemicals in cigarette smoke may act with nicotine to make it harder to quit smoking. The effects of smoking on monoamine oxidase (a brain chemical) is still being studied. For some people, withdrawing from smoking causes more severe mood problems, which can result in worse cravings and more trouble staying quit.
Smoking affects other medicines
Smoking also makes your body get rid of some drugs faster than usual. When you quit smoking, it may change the levels of these drugs. Though it’s not truly withdrawal, this change can cause problems and add to the discomfort of quitting. Ask your doctor if any medicines you take need to be checked or changed after you quit.
Last Revised: 02/06/2014