What Happens When You Quit Smoking?

Dr. Patrick Carroll, MD

Medically reviewed by Patrick Carroll, MD

Written by Our Editorial Team

Last updated 9/19/2019

There was a time when it seemed like everyone smoked. We smoked on planes, in restaurants, in our vehicles with the windows closed and in our homes. But back then, we were only beginning to realize the dangers of smoking — now, we know better. 

From 2005 to 2017, the number of adults who smoke has declined from 21 percent to 14 percent, according to the CDC. In 1965, 42 percent of American adults smoked. 

People are quitting. It’s not easy, but people are doing it in droves. They’re doing it for obvious reasons — their health, mainly, as the costs of smoking far outweigh the only benefit: the pleasure of feeding an addiction. 

Quitting smoking isn’t easy. In fact, it’s extremely difficult. But understanding what’s in it for you may give you the added motivation to get through the toughest cravings. 

How Smoking Changes Your Body 

Cigarettes are loaded with harmful chemicals — some 5,000 of them, according to the CDC and American Heart Association. These chemicals — including arsenic, cadmium, formaldehyde, tar, carbon monoxide and nicotine — can cause significant damage to your body. 

Cigarette smoking can:

Really, this list could go on and on. And we haven’t even touched the psychological and social effects of smoking. Smoking can be an isolating habit (it even limits the availability of potential mates) and addiction doesn’t do you any favors in fighting off depression.

There are plenty of reasons to quit smoking, not the least of which is your health. Here’s what you have to look forward to by setting aside cigarettes for good.  

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What Happens When You Quit: The Timeline 

Your body begins changing soon after finishing your last cigarette. In other words, each cigarette you put out is an opportunity to reclaim your body and health. The health benefits of quitting smoking are many. Here’s how they break down over time:

Within the first hour: 

  • Your heart rate returns to normal levels within just 20 minutes of your last cigarette.

Within the first day: 

  • Oxygen levels within your blood return to normal within eight hours

  • Nicotine and carbon monoxide levels within your blood are reduced by half.

  • You begin saving money! 

Within the first three days: 

  • Nicotine has completely left the body within two days

  • Carbon monoxide has completely left the body within two days. 

  • Mucus begins to clear from your lungs. 

  • Breathing becomes easier.

  • Energy levels increase. 

  • Taste and smell improve. 

  • People at work stop resenting you for your smoke breaks!

Within the first weeks: 

  • Circulation improves within two to 12 weeks. 

  • Lung function continues to improve. 

  • Your heart attack risk begins to drop. 

  • You stop smelling like an ashtray!

Within 3 to 9 months: 

  • Cilia in your lungs (tiny hairs that control mucus) return to normal function.

  • The risk of infection is reduced. 

  • Coughing decreases.

  • Lung function increases by up to 10 percent. 

  • You stop finding ashes, lighters and butts around your home and vehicle!

Within the first year: 

  • Your risk of heart disease is reduced to half of that of a smoker. 

  • Heart attack risk drops “dramatically.”

  • You begin feeling like a true nonsmoker, not someone who just quit!

Within five years:

  • Your risk of stroke falls to that of a non-smoker. 

  • Mouth, throat, esophageal and bladder cancer risks are cut in half. 

  • You start resenting secondhand smoke and consider giving smokers dirty looks (don’t do it)!

After a decade:

  • Risk of death by lung cancer is half that of a smoker’s.

  • Risks of kidney, larynx and pancreatic cancers further decreases. 

  • You find it hard to believe you were once a slave to nicotine!

After 15 years of not smoking: 

  • Your risk of heart disease returns to that of a nonsmoker. 

  • People are surprised when you tell them, “I used to be a smoker.”

Of course there will be other improvements along your quitting smoking journey — at some point your skin will improve, your immune function will be more robust, your risk of type 2 diabetes will drop and, if things weren’t working quite well before, your bedroom performance should begin to improve.

Additional Benefits of Quitting Smoking 

When you quit smoking, you begin creating a new you. Quite literally, your body begins undergoing changes that have the potential to change your life. All of the horrible things smoking caused begin falling away — and let’s be frank, those “horrible things” weren’t only physical effects. 


People who smoke are more likely to suffer from depression, according to the National Institutes of Health. Exactly why this is isn’t clear. Smoking does trigger the release of dopamine (a pleasure chemical) in the brain, and it’s believed people with depression take advantage of this rush of feel-good chemicals, only to crash when the nicotine wears off. 

It’s a chicken-egg scenario, where researchers aren’t sure if depression increases the likelihood of you becoming a smoker or vice versa, but quitting smoking can certainly help you find more appropriate ways of managing your mental health.  

Stress management 

The dopamine dump that happens when you smoke can make it feel like your cigarettes are a helpful tool in stress management. But they’re not. 

The dopamine is hiding an increased heart rate, higher blood pressure, muscle tension and decreased oxygen levels — real physical effects of smoking. When you’re addicted to smoking, you’re essentially tricked into higher stress levels. Putting the smokes down will eventually help you relax. 

Social isolation

Smokers are a unique community, but that community is ever-shrinking. As a smoker, you must increasingly hunt down private places to enjoy your addiction, and your colleagues, friends and family may not be likely to follow. 

Lack of control 

Addiction controls your life when you’re a smoker. It dictates where you go and how you time your day. On a road trip? Unless you’re smoking in the car, you’ll likely need just as many smoke breaks as pee breaks. At work? You likely count down until your next opportunity for a cigarette. Quitting smoking lets you regain the control you’ve handed over to nicotine. 

Getting Help

There are numerous resources out there to help people successfully quit smoking. But no one can do it for you, and it won’t be easy. 

Smokefree.gov suggests making a quit plan. By solidifying your plan to quit, you’re making a commitment to yourself. That plan involves setting a quit date, identifying your triggers, listing your motivators, preparing to fight cravings, getting rid of reminders of your addiction and getting help. 

You can also talk with your doctor about various medical tools that may help. Nicotine replacement tools like patches, gums and inhalers can help you wean your addiction and minimize nicotine withdrawals. 

You’re not alone when you quit tobacco. Pick up the phone to call someone who’s been through it before — you likely have friends who are former smokers. Also, download an app for smoke-free tools at your fingertips. 

The list of benefits to quitting is long and the risks of not-quitting are deadly, so seriously consider changing your life today.

This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.

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