Here’s what happens to your body when you quit smoking- National Geographic


April 6, 2024

This is an excerpt from National Geographic. 

The risks of smoking are well-known. Here are the immediate and long-term health benefits of quitting.

Every year, half a million Americans die from smoking – related causes, while an estimated 16 million Americans are living with smoking-related chronic health conditions, such as chronic obstructive pulmonary disease, heart disease, stroke, or cancer. Although the risks of smoking are well- known, it’s also incredibly challenging to quit, leading many to give up, assuming the damage has been done. However, as research is consistently showing, there is a significant upside. To get a sense of what these short- and long-term health benefits are, National Geographic spoke with some experts about what happens in your body in the hours, days, weeks, months, and years after quitting.

Improved heart rate and breathing

Those who give up smoking can expect their heart rates and breathing to improve. The first change, which can happen within hours of quitting, is a decrease in heart rate, says Humberto Choi, a pulmonologist at the Cleveland Clinic. The elevated carbon monoxide levels in the blood found in smokers (roughly three times higher) also return to normal within days. Over the course of weeks, other changes kick in. One of the major ones is that lung function improves and coughing decreases, which can help improve exercise capacity. These changes help people breathe a little easier, while also making it a little less challenging to develop and maintain an exercise habit—such as going for regular walks or fitting in a morning strength-training routine. “In general, people tend to feel better,” Choi says. Exercise also offers an alternative habit to replace smoking. “The habit doesn’t go away fast,” Choi says. “It’s good to add something else in.” Many people also report a better sense of smell and taste in the weeks and months after quitting. “Sometimes they didn’t even realize they lost the sense of smell and taste,” Choi says.

Sharp reduction in risk for heart attack or stroke

As the months stretch into years, quitting smoking can lead to a drastic reduction in risk for developing cardiovascular disease, such as a heart attack or stroke. “In the first two years after quitting, you lose a lot of the excess risk,” says Marie Robertson , a cardiologist who serves as the chief science officer for the American Heart Association As Robertson notes, this risk continues to drop the longer a person stops smoking. By the 10-year mark, the risk of dying from cardiovascular disease drops by 63 percent, compared to smokers. After 20 to 30 years, this risk drops to similar levels as that of someone who has never smoked.

Cancer risk drops after a decade

As time progresses, the risk for developing certain types of cancer also drops. Around the 10 – year mark is when this risk declines substantially. “After  10 years, the risk for death [from] lung cancer is half the risk of current smokers,” says Farhad Islami, the senior scientific director for the American Cancer Society, and a researcher who studies cancer risks in various populations There is a similar reduction in risk for other types of smoking-related cancers, such as head, neck, or esophageal cancers, Islami says. In a recent paper Islami co-authored, he and his colleagues found that 20 to 29 years after quitting, the risk  of dying from cancer drops by about 90 percent. For people who were able to quit before the age of 35, there is an even greater reduction in risk, to the point that over a period of two to three decades their risk of dying from smoking-related cancers becomes almost equivalent to a person who has never smoked. “It’s best if you quit smoking at an earlier age,” Islami says. But, he adds, even if people aren’t able to quit until they are older, “the benefits are still very, very substantial.”

Progression of smoking-related conditions slows

For people who are living with smoking-related chronic health conditions, such as cancer, heart disease, or chronic obstructive pulmonary disease (COPD), quitting can slow the progression of disease, while also improving the odds of survival. “The chance of having a recurrence after cancer is lower if you quit smoking,” Choi says. For people who have already had a heart attack, quitting can reduce the chance of having a second one and lower the likelihood of COPD getting worse. “We want people to quit before they develop those conditions,” says Luba Yammine, a researcher at UTHealth Houston, whose research focuses on substance use disorder, adding that “if you have already developed the disease, it is still going to be of great benefit to quit smoking.”

Addiction is complex

Smoking can be one of the hardest addictions to break, due to a number of factors. “Nicotine is the most addictive substance there is,” Yammine says. “It’s very easy to get addicted and very difficult to quit.” The difficulties in quitting are due to a mixture of physical and behavioral factors. The first challenge is due to physical dependence on nicotine, which can cause a combination of cravings and withdrawal symptoms after quitting. “This combination of cravings and withdrawal symptoms is quite unpleasant,” Yammine says. Many people report experiencing excess hunger after quitting, along with general feelings of irritability. In order to help reduce these symptoms, there are a number of tools available, including nicotine patches and gum, or medications such as bupropion. The second major factor, that makes quitting so difficult, is behavioral. “Cigarettes become a very integral part of your life,” Yammine says. For a long-term smoker, their day is often structured around when and where they smoke, whether it’s having a cigarette with their morning coffee, taking periodic smoke breaks throughout the day, or lighting up in specific environments. These behaviors can become so engrained that it becomes very difficult to break the habit, even if the physical symptoms of withdrawal are well-controlled.

Quitting often requires multiple attempts

Due to the difficulties associated with nicotine addiction, smokers report many attempts at quitting, before they are able to find a successful strategy; and what ultimately works for one person may not work for another. While quitting cold turkey works for some, others need the assistance of medication to curb their cravings. Some people must make major changes to their daily habits to quit, while others may succeed with just minor adaptations. Some quit after the first few tries; for others it takes many attempts. “Each try is a lesson about how to do it better the next time,” Robertson says.


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