Smoking Cessation Timeline: What Happens When You Quit

Reading time: 6 – 9 minutes

In the U.S., one-quarter of adults 18 years of age and older smoke cigarettes [1]. Smoking is truly a deadly habit. With about 4000 known chemicals in tobacco smoke, more than 50 of them are known to cause cancer. According to the World Health Organization, every six seconds someone in the world dies from tobacco use [2].

How’s this for bad odds: tobacco kills 50% of its regular users. One out of every two regular smokers will die from smoking [2].

cigarette-clock.jpgIn addition, an estimated 200,000 people die every year due to second-hand smoke exposure at work. The United States Environmental Protection Agency estimates that second-hand smoke is responsible for approximately 3000 lung cancer deaths annually among non-smokers [2]. Additionally, new research has linked second-hand smoke exposure to psychological problems in children, including attention deficit disorder (ADHD) and conduct disorder.

The best time to quit smoking is RIGHT NOW. And while quitting is tough, you can start counting the benefits of not smoking in as little as 20 minutes. Here’s what happens to your body when you quit smoking [3-5]:

Smoking cessation timeline – the health benefits over time

  • In 20 minutes, your blood pressure and pulse rate decrease, and the body temperature of your hands and feet increase.
  • Carbon monoxide in cigarette smoke reduces the blood’s ability to carry oxygen. At 8 hours, the carbon monoxide level in your blood decreases to normal. With the decrease in carbon monoxide, your blood oxygen level increases to normal.
  • At 24 hours, your risk of having a heart attack decreases.
  • At 48 hours, nerve endings start to regrow and the ability to smell and taste is enhanced.
  • Between 2 weeks and 3 months, your circulation improves, walking becomes easier and you don’t cough or wheeze as often. Phlegm production decreases. Within several months, you have significant improvement in lung function.
  • In 1 to 9 months, coughs, sinus congestion, fatigue and shortness of breath decrease as you continue to see significant improvement in lung function. Cilia, tiny hair-like structures that move mucus out of the lungs, regain normal function.
  • In 1 year, risk of coronary heart disease and heart attack is reduced to half that of a smoker.
  • Between 5 and 15 years after quitting, your risk of having a stroke returns to that of a non-smoker.
  • In 10 years, your risk of lung cancer drops. Additionally, your risk of cancer of the mouth, throat, esophagus, bladder, kidney and pancreas decrease. Even after a decade of not smoking however, your risk of lung cancer remains higher than in people who have never smoked. Your risk of ulcer also decreases.
  • In 15 years, your risk of coronary heart disease and heart attack in similar to that of people who have never smoked. The risk of death returns to nearly the level of a non-smoker.

Why is it so difficult to quit smoking?

In one word … nicotine.

Nicotine is an organic compound known as an alkoloid (meaning a nitrogen-containing ring compound, usually water-insoluble and alcohol soluble) found in the leaves of several species of plants, predominantly tobacco, as well as in lower quantities in several frequently consumed vegetables from the nightshade or Solanaceae family, including tomatoes, potatoes, aubergines (eggplant) and peppers [6]. Nicotine by itself is not carcinogenic [7]. However, it does inhibit UV-induced activation of cell death (a process known as apoptosis) [8], interfering with the body’s ability to destroy potentially cancerous cells.

Nicotine activates a specific type of neurotransmitter receptor – the acetylcholine receptor – an integral membrane protein widely distributed in the brain and neuromuscular junctions that normally responds to the binding of the neurotransmitter acetylcholine. This is nicotine’s addictive property: activation of acetylcholine receptors leads to an increased flow of adrenaline (epinephrine), which increases the heart rate, blood pressure, respiration and glucose levels in the blood.

When smokers try to cut back or quit smoking, they experience nicotine withdrawal. A regular smoker will have nicotine or its by-products present in their body for 3 to 4 days after quitting [9]. Withdrawal symptoms appear within a few hours and peak 24 to 48 hours after quitting [10]. Withdrawal symptoms include tobacco craving, a desire for sweets, increased coughing and impaired performance on tasks that require concentration [10-11]. Most symptoms last an average of one month, but hunger (due to the lack of increased blood glucose) and craving can last 6 months or more [10].

Did you ever smoke? How hard was it for you to quit? How did you do it?


  1. 2005 National Survey on Drug Use & Health Results. U.S. Department of Health and Human Services. Substance Abuse and Mental Health Services Administration. Office of Applied Studies. 2005.
  2. 10 Facts About Tobacco and Second-hand Smoke. World Health Organization.
  3. Quitting Smoking: Why To Quit and How To Get Help. National Cancer Institute.
  4. Quit Smoking – Smoking Cessation Support – Benefits. American Lung Association.
  5. When Smokers Quit – The Health Benefits Over Time. American Cancer Society. Revised 10/25/2006.
  6. Siegmund et al. Determination of the nicotine content of various edible nightshades (Solanaceae) and their products and estimation of the associated dietary nicotine intake. J Agric Food Chem. 1999 Aug;47(8):3113-20.
    View abstract
  7. Dasgupta and Chellappan. Nicotine-mediated cell proliferation and angiogenesis: new twists to an old story. Cell Cycle. 2006 Oct;5(20):2324-8. Epub 2006 Oct 16.
    View abstract
  8. Sugano et al. Nicotine inhibits UV-induced activation of the apoptotic pathway. Toxicol Lett. 2001 Dec 15;125(1-3):61-5.
    View abstract
  9. Guide to Quitting Smoking. American Cancer Society. Revised 10/27/2006.
  10. Hughes and Hatsumkami. The nicotine withdrawal syndrome: A brief review and update. International Journal of Smoking Cessation. 1992 1:21-26.
  11. Hughes, Higgins and Hatsukami. Effects of abstinence from tobacco: a critical review, in Research Advances in Alcohol and Drug Problems, vol 10. Edited by Kozlowski LT, Annis HM, Cappell HD, Glaser FB, Goodstadt MS, Israel Y, Kalant H, Sellers EM, Vingilis ER. New York, Plenum, 1990, pp 317-398.
About the Author

Walter Jessen is a senior writer for Highlight HEALTH Media.


  1. What an interesting article. I’m going to email this to one friend and print it off to show another.

    One of the side effects not listed was a change for a time in their disposition – to put it nicely. I know someone that quit smoking the day of their heart attack. He was 42 with three blockages, he luckily survived. He quit cold turkey that day! But, oh boy the people around him suffered. He was a ornery cuss for a while. Not pleasant, but worth it!

  2. That’s really interesting, I’ve never started smokig or even plan to. Like Chrysalis I’m going to show some of that stuff to a friend of mine, give him some food for thought.

  3. Word Hugger says:

    That is an interesting article, and it looks like you did a lot of research. My motto; Don’t start, no problems 🙂

  4. Kick me. I had quit for 5 years and it was completely out of my system. My now-wife then-girlfriend smoked, and I grabbed one out of her hand to prove to myself that I couldn’t smoke again if I wanted to. The next day I bummed smokes off a guy at work. The next day I bought a pack. Two days later I bought a carton. Insidious.

  5. Chrysalis Angel – disposition is a side effect that’s difficult to quantitatively measure. You’re absolutely right however … it’s not pleasant but definitely worth it when friends or loved ones quit smoking.

    mlankton – you’ve quit once before, so you know you can do it. Focus on the benefits of not smoking and this time, once you’ve kicked the habit, don’t smoke again!

    Word Hugger and Spitfire – thanks for your comments. Outbound links are the least I can do for someone who has spent time on a meaningful comment. Please feel free to contribute to the discussion in the future.

  6. Could anyone tell me which, if any, would be worse in terms of risk:

    a) smoking 3 packs per day for 3 years?

    b) smoking 1 pack per day for 9 years?

    i.e. is it the total number of cigarettes smoked over a lifetime that determines risk, or is there more to it than that?

  7. I smoked a pack and a half a day for about ten years straight. I managed to quit for good 1 year and 10 months ago. My computer tells me that I have avoided smoking over 17,000 cigarettes in that amount of time, and saved over $2,600 dollars.

    But the real shocker to me is the amount of time I would have spent physically smoking those 17 thousand cigarettes-over 59 days! To me that is unbelievable.

    This means that for a pack a day smoker, you are spending almost an entire month out of each year engaged in the act of smoking. That is a lot of time and lost productivity! And just think how much harder it is getting to smoke in public places….you have to constantly go out of your way in order to smoke.

    Just not worth it anymore. Check my website if you want to see how I managed to finally quit.

  8. i quit smoking six days ago with the help of chantix a new drug. its like magic i smoked two packs a day i started taking the pills , and 8 days later i quit smoking with no withdrawl symptoms. i feel bad for anybody who has tried to quit any other way.

  9. Ian – I’ll have an answer for you shortly. I thought others would be interested in the answer, so I’m writing up an article on it.

    Patrick and thom – congrats on quitting!

    Thanks to all of you for your comments.

  10. My life partner started smoking when he was 7 years old. For several years I have been trying to encourage him to stop. Even when we discovered I was ill in 2003, he still continued to smoke even in my presence.

    Fortunately, at the beginning of this year, he stopped. As in totally stopped. (He is now 57 years old).

    I asked him why and he said he was doing it for me. 🙂
    Swell. Sigh! Better late than never, that was my only reaction.


  11. lotusflower – your partner started smoking at seven years old? … Wow! If he’s been smoke-free for 10 months now, hopefully he’s past the hunger and cravings. I’ve known people who smoked many, many years and quit. It can be very difficult to stay smoke-free, especially during times of stress. Keep supporting him!

    Thanks for stopping by and your comments!

  12. I am 1 day quit with Chantix – I agree Thom! It is miraculous! Other than getting used to not having a smoking routine, it’s been amazingly easy – no physical withdrawl.

    I started smoking at 12. I am 41, and had a stroke last month. It wasn’t attributed to my smoking, but what a wake-up call. I’m quit for good!!!!


  13. This is Thom again still a non smoker ive even started jogging. I cant remember feeling so good keep it up everybody. If anyone would like some support feel free to e mail me at

  14. Everyone: I published a new article that discusses Smoking Duration vs. Intensity and the Impact on Lung Cancer Risk.

    Thanks for your question Ian!

  15. Forthekids says:

    I recently stopped smoking after several attempts using pills, patches and gums. I was successful when I read alan carr’s book “the easy way to stop smoking.” It is trully a miracle.

  16. WTG Thom 🙂

    I’m comfortably on day 2 – NO cravings!

  17. Hello all, I have spotted Allen Carr mentioned in the list of comments, I would like to add that the book “Easyway to stop smoking” is a true miracle, if your interested in stopping smoking I would definatly recomend this book to you.

    Allen Carr’s Easyway to stop smoking

    I have successfully stopped smoking using the method in this book. I had virtually no withdrawal symptoms at all, and have found it very easy to stop, where I would normally be bounsing off the walls.

    I wish you all the best of luck, and remember it isnt that hard if you put your mind to it.



  1. […] Update: Walter at Highlight Health has more on what happens when you quit smoking. […]