DaymarkIf you have just put out your last cigarette, or you are about to, the first question is usually: what is going to happen to my body, and when? Health organisations publish "quit smoking timelines" that answer it. This guide walks through what the CDC, the American Cancer Society and the NHS actually say, in order, and is careful about what is a documented milestone and what is only a general benefit. It also shows how to turn the timeline into something you can check off yourself.
One note first. This is general information from public health sources, not medical advice. Timelines describe average changes in risk and in the body; they are not promises for any one person. If you have a health condition, or you take medication, talk to a doctor or pharmacist about quitting.
How to read a quit smoking timeline
Three things are worth knowing before the dates.
- Early items are body changes; later items are risks. "Heart rate drops" is something that happens within minutes. "Risk of heart attack drops" is a statistical statement about a group of people, compared with people who keep smoking.
- The comparison is with continued smoking. The CDC states that the risks it lists are compared to continuing to smoke. A lower risk is not the same as no risk.
- Sources round differently. The CDC, the American Cancer Society and the NHS present slightly different time points. Where they differ, this page says so instead of picking one silently.
The first minutes and the first day
The earliest entry on the American Cancer Society's list is "a few minutes after quitting": your heart rate drops. The CDC's table says the same, that heart rate begins to fall within minutes. The NHS describes a pulse beginning to return to normal after about 20 minutes. These are similar statements in different words, not a contradiction.
The next milestone is about 24 hours. According to the CDC, nicotine in the blood falls to zero after 24 hours. The American Cancer Society groups this under "24 hours to a few days after quitting": nicotine levels in your blood drop to zero, and the carbon monoxide level in your blood drops to normal. The NHS puts carbon monoxide at a non-smoker's level within 48 hours. If you need one practical point from this section, it is that by the end of the second day the measured chemistry of your blood has already moved.
It is also worth saying plainly what these sources do not claim: that the first days feel good. Nicotine leaving the body is exactly why many people find the first days the hardest. The CDC links to guidance on identifying and handling withdrawal symptoms, and the NHS has pages on cravings and staying smoke-free. The sources I read for this article do not give a reliable length for how long cravings last, so I will not either. If the first week is rough, that is common, and it is a good moment to use a quitline (see the end of this guide).
Days to weeks
Between the first few days and the first month, the milestones in the public sources are mostly about the carbon monoxide result you already have and about how you feel in ordinary activity. The American Cancer Society says that you may notice improved taste, smell and breathing during ordinary activity, and that you save the money you would have spent on tobacco, straight away. There is no precise day-by-day schedule here, and it would be invented to pretend there is.
The NHS suggests a goal for this stretch: aim for 28 smoke-free days. Reaching that point, the NHS says, makes a lasting quit much more likely. That is a useful target because it is short enough to see and concrete enough to count. Our guide to tracking a quit attempt covers how to count days and what to do if you slip before you get there.
One to twelve months
The American Cancer Society and the CDC both list the same change here: between one and twelve months after quitting, coughing and shortness of breath decrease. That is the most noticeable item for many people, because it is something you can feel on the stairs or on a walk.
One to two years: heart attack risk
At one to two years after quitting, the CDC and the American Cancer Society say your risk of heart attack falls sharply (the American Cancer Society's word is "dramatically"). The NHS gives a one-year figure in simple terms: after one year, your heart attack risk is roughly half that of a smoker. These are slightly different framings of the same area of benefit. If you are quoting one, quote the source with it.
Three to ten years
This is where the timeline shifts from how you feel to how risk accumulates.
- 3 to 6 years (CDC): the extra risk of coronary heart disease is cut in half.
- 5 to 10 years: the extra risk of cancers of the mouth, throat and voice box (larynx) is cut in half, and the risk of stroke declines. Both the CDC and the American Cancer Society list this.
- 10 years: the American Cancer Society says your risk of lung cancer is about half that of a person who is still smoking, and the risk of bladder, oesophagus and kidney cancers decreases. The CDC says the extra lung cancer risk is cut in half by 10 to 15 years. The NHS says that after ten years your risk of dying from lung cancer is roughly halved.
Notice how the wording differs: "risk of lung cancer", "extra risk", "risk of dying". These are not interchangeable, and I would rather you see the original wording than a single clean number.
Fifteen to twenty years
At 15 years, the CDC and the American Cancer Society say the risk of coronary heart disease is close to that of someone who has never smoked. At 20 years, the American Cancer Society says the risk of several cancers drops to close to that of someone who does not smoke, and the added risk of cervical cancer drops by about half. The CDC lists mouth, throat, voice box and pancreatic cancers as nearing a non-smoker's risk at 20 years.
Beyond the dates
The CDC also lists broader benefits of quitting that do not have a specific day attached: a lower risk of premature death, a lower risk of 12 types of cancer, lower risk of stroke, and a lower risk of developing COPD along with slower progression for people who already have it. The CDC says some of these, such as a lower risk of atrial fibrillation and heart failure, "may" occur, and it is worth keeping that hedge when you repeat them.
The American Cancer Society adds a line that surprises people: quitting before age 40 reduces the risk of dying from smoking-related disease by about 90 percent, and quitting at any age can add years to your life. The CDC says possibly up to 10 added years of life expectancy. "Never too late" appears in the NHS summary, too.
Make your own timeline
A published timeline is general. The version that motivates you is the one with your own start date on it. Here is a simple way to build it.
- Write the date and time of your last cigarette. The early milestones (20 minutes, 24 hours, 48 hours) are measured from that moment.
- Pick three checkpoints you can reach soon: day 2, day 28 and month 3, for example. Short checkpoints give you something to reach this month, while the ten-year numbers stay in the background.
- Count clean days, and keep a second number. Days since your last cigarette is the motivation number. Total smoke-free days in this attempt is the honest number if you slip. A slip then costs you one day, not the whole story.
- Add the money. The money you do not spend is the one benefit you can measure every morning. Use our money-saved calculator; it works from what you used to spend per day.
- Write down your triggers. After coffee, after meals, at the end of a stressful call. A one-line note each time shows patterns within a week or two.
You can do all of this on paper. If you prefer an app, Daymark has a quit counter that shows days since your last cigarette and money saved next to your other habits; see the home page. The tool matters much less than the habit of looking at the number.
If you slip
A slip is information, not a verdict. Record it honestly, note what the trigger was, and restart the clock the same day. Do not treat one cigarette as the end of the attempt; ask a quitline or your doctor how to get back on track. Our guide to restarting after a missed day applies to quit counters as well.
Where to get help
You do not have to do this alone. In the United States, the CDC lists 1-800-QUIT-NOW (1-800-784-8669) as a telephone resource. In the UK, the NHS offers a free Personal Quit Plan, a free NHS Quit Smoking app that tracks progress and savings, and local Stop Smoking Services. If you are elsewhere, your national health service or doctor can point you to a local quitline. Whether to use nicotine replacement or other medicines is a decision for you and a clinician; this page does not recommend any treatment.
Daymark and this website are not medical services. If you have chest pain, severe breathlessness or any symptom that worries you, contact a doctor.
Frequently asked questions
What happens 20 minutes after you quit smoking?
The CDC and American Cancer Society say heart rate begins to drop within minutes of quitting. The NHS describes the pulse beginning to return to normal after about 20 minutes.
How long until nicotine leaves the body?
The CDC and the American Cancer Society both say nicotine in the blood drops to zero about 24 hours after the last cigarette (the American Cancer Society says 24 hours to a few days).
When does breathing get better after quitting smoking?
The CDC and the American Cancer Society say coughing and shortness of breath decrease between 1 and 12 months after quitting.
When does heart attack risk go down after quitting?
The CDC and the American Cancer Society say heart attack risk falls sharply 1 to 2 years after quitting. The NHS says that after one year the risk is roughly half that of a smoker.
Is it ever too late to quit smoking?
The NHS says it is never too late to quit, and the American Cancer Society says quitting at any age can add years to your life.
