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How understanding the science behind smoking can help you to stop

a photo of Caroline Wood
Head of Behavioural Insights and Research at Bupa UK
15 November 2021

If you’re struggling to stop smoking, you’re not alone. You might believe it’s a lack of willpower that’s stopping you from giving up. This might make you feel guilty and defeated. But in fact, smoking causes a reaction in your body and mind that makes quitting hard.

Understanding why smoking is so addictive, and getting the right help and support, can give you the tools you need to quit.

Here, I explain the science behind why smoking is so addictive and how to use this knowledge to help you to stop.

Why is smoking so addictive?

When you smoke, you inhale (breathe in) a substance called nicotine. This travels to your brain via your bloodstream. Nicotine is extremely addictive. This is mainly because it makes you feel good. Nicotine triggers receptors (special cells that receive chemical messages) in your brain to release a ‘happy hormone' called dopamine. Dopamine helps you to feel good both physically and mentally.

Once you’ve smoked for a while, your brain starts to expect nicotine in order to get a dopamine rush. To make matters harder, the more you smoke, the more nicotine receptors you grow. This means it can take more and more nicotine to give you the dopamine that your mind and body crave. You may start to get cravings and withdrawal symptoms if you reduce your intake.

The good news is, as soon as you stop smoking, the amount of nicotine receptors in your brain start to reduce. This makes your cravings less strong and less often.

Why is it hard to quit smoking?

Stopping smoking is hard for two main reasons. Firstly, nicotine is addictive for your body and brain, which is why you can get hooked on it. But also, your behaviours and routines can keep you going back for more.

Physical reasons

It’s normal to want to do things that make you feel good. Your brain even ‘rewards’ you for doing these things. So you’ll want to repeat anything that feels nice and triggers dopamine, like eating and drinking.

Smoking gives you a very quick and strong surge of dopamine, which you’ll come to rely on. This explains why it can be tough to stop.

You can’t change the physical processes involved in addiction. But you can take some simple steps to change certain behaviours and routine which can help you to stop.

Behavioural reasons

You will have certain daily routines, like drinking coffee in the morning or relaxing with some TV in the evening. Sometimes, these routines can be triggers for you to smoke. This happens when your brain associates a habit or behaviour with nicotine. So, if you always smoke after dinner, you might find this a challenging time of day when you’re trying to quit.

Another reason stopping smoking can be tough is due to something known as the ‘present bias’. Naturally, you’re more motivated by short-term benefits. It takes a lot of patience and motivation to achieve longer-term goals. To quit, you have to push through the short-term struggle of cravings in order to get the longer-term benefits of quitting.

How can you quit smoking for good?

When you first decide to stop smoking, you need to help your body adjust to life without nicotine. Often a combination of different things can help you. You might benefit from a mix of expert support, more exercise and avoiding your smoking triggers.

You have several tools to choose from. Here are a few for you to try.

Change your mindset

From the moment you decide to stop smoking, consider yourself an ex-smoker. See yourself as someone ‘who used to smoke’ instead of someone who is ‘trying to quit’. This sends a powerful message to your brain that you’re serious about stopping. Some studies show that if you think this way you’re more likely to quit smoking for good.

Stick to the ‘not a puff’ rule

It can be tempting to just cut down on cigarettes. But this doesn’t help you to break the habit of smoking and makes relapse more likely. Instead, it’s much more helpful to stop completely.

Consider what you lose by smoking

You might think it’s good to consider what you gain by not smoking. But you may be better off focusing on what smoking is costing you, either personally or financially. This is due to something known as loss aversion – you would rather avoid losing something than gaining something of the same value. You could think about how much money you lose each month by smoking as a way to motivate you to stop. Here’s a handy tool to help you calculate this amount.

Ask for help and support

Stopping smoking is best done with the support of others. Studies show this approach is much more effective than going it alone.

The following may help.

  • If you feel comfortable to do so, share your commitment to quitting smoking with friends and/or family. This helps to hold you accountable and may boost your motivation to succeed. You might even find you inspire others to quit with you.
  • Connect to a free smoking support service, via your GP or online.
  • Use an evidence-based app (eg, NHS Quit Smoking, Smoke Free – Stop Smoking Now) to help set your goals and track your progress. Switch to nicotine patches or other forms of nicotine replacement therapy to help manage any cravings. This includes nasal sprays or e-cigarettes.

How to manage your smoking triggers

  • Understand your triggers. Everyone is unique. Take the time to understand your triggers to help you plan ahead, avoid them or manage them if they do arise.
  • Have a plan of action. Have go-to strategies in place that you can turn to if you’re tempted to smoke. This can really reduce your chances of relapse. One simple idea is taking five deep breaths to help you relax.
  • Remove temptation. Avoid the sights and smells of smoking. Seeing someone smoking, or even smelling a cigarette, can result in cravings. Throw away any ashtrays, tobacco packets and lighters. Also clean any fabrics that hold onto the smell of smoke, such as curtains, clothing or blankets.
  • Distract yourself. Cravings only last for around five minutes, so by the time you’ve rung a friend, watched a funny video or played with your dog, they should have passed. You can then move on with your day.
  • Chew something. The act of smoking can become a soothing ritual. You can replace this with chewing something instead. Try chewing sugar free gum or eating vegetable sticks to keep your mouth and hands occupied.
  • Change your routine. If you usually end your meal with a cigarette, consider eating a piece of dark chocolate or drinking a cup of tea instead. This will reinforce a new healthier routine.

Improve your physical health

Exercising

Regular exercise can help reduce both withdrawal symptoms and cravings, meaning you’re less likely to start smoking again. Exercise plays an important role in maintaining your mental and physical wellbeing. It can naturally regulate your happy hormones, including dopamine and serotonin.

Even small boosts to your mood from exercise can:

  • help you to cope with stress better
  • increase your resilience to stop you slipping back into old habits

Eating well

Try to eat a well-balanced diet, focusing on fresh and unprocessed wholefoods such as vegetables, fruits, protein and healthy fats. Not only does a healthy diet improve your general health and wellbeing but interestingly, eating foods such as veg, fruit, and dairy can make smoking taste bad. This can help to discourage you from doing it after a meal. Also, make sure you don’t get hungry, as this can help you to avoid mistaking hunger for nicotine cravings.

Now you know that smoking changes your brain chemistry in a way that can make it hard to stop. But also, that the way you act and the things you do can keep you addicted.

Seeking help, managing your triggers and prioritising your physical health can all help. So, don’t go it alone – find the support you need to help you move on from smoking for good.


Do you know how healthy you truly are? Bupa health assessments give you a clear overview of your health and a view of any future health risks. You'll receive a personal lifestyle action plan with health goals to reach for a happier, healthier you.

a photo of Caroline Wood
Caroline Wood
Head of Behavioural Insights and Research at Bupa UK

    • How to support your quitter. Smokefree.gov. smokefree.gov, accessed 27 October
    • Roh S. Scientific evidence for the addictiveness of tobacco and smoking cessation in tobacco litigation. J Prev Med Public Heal 2018; 51:1–5. doi:10.3961/jpmph.16.088
    • Why quitting is hard. Smokefree.gov. smokefree.gov, accessed 27 October 2021
    • Smoking and mental health. Mental Health Foundation UK. www.mentalhealth.org.uk last updated 9 March 2021
    • Farhud DD, Malmir M, Khanahmadi M. Happiness & health: The biological factors - systematic review article. Iran J Public Health 2014; 43(11):1468–77
    • Benowitz NL. Pharmacology of nicotine: Addiction, smoking-induced disease, and therapeutics. Annu Rev Pharmacol Toxicol 2009; 49:57–71. doi:10.1146/annurev.pharmtox.48.113006.094742
    • Abstinent smokers’ nicotinic receptors take more than a month to normalize national institute on drug abuse. www.drugabuse.gov, published 1 October 2009
    • Understanding withdrawal. Smokefree.gov. smokefree.gov, accessed 21 October 2021
    • Why is it so hard to quit smoking? The British Psychology Society. www.thepsychologist.bps.org.uk, published May 2013
    • Nicotine and addiction. Action on smoking and health. ash.org.uk, published 1 August 2018
    • Present bias. Behaviour Economics. behavioureconomics.com, accessed 9 November 2021
    • Why is it so hard to stop smoking? British Lung Foundation. www.blf.org.uk, accessed 27 October 2021
    • Tombor I, Shahab L, Brown J, et al. Does non-smoker identity following quitting predict long term abstinence? Evidence from a population survey in England. Addict Behaviour 2015; 45:99–103. doi:10.1016/j.addbeh.2015.01.026.
    • Health matters: stopping smoking – what works. GOV.UK. www.gov.uk, updated 17 December 2019
    • Stop smoking services to help you quit. NHS. www.nhs.uk, reviewed October 2018
    • Risk factors – smoking. British Heart Foundation. www.bhf.org.uk, last updated September 2021
    • Klinsophon T, Thaveeratitham P, Sitthipornvorakul E, et al. Effect of exercise type on smoking cessation: A meta-analysis of randomized controlled trials. BMC Res Notes 2017. doi:10.1186/s13104-017-2762-y
    • Lin TW, Kuo YM. Exercise benefits brain function: The monoamine connection. Brain Sci 2013; 3(1):39–53. doi:10.3390/brainsci3010039.
    • Ussher M, Nunziata P, Cropley M, et al. Effect of a short bout of exercise on tobacco withdrawal symptoms and desire to smoke. Psychopharmacology 2021; 158(1):6672. doi: 10.1007/s002130100846
    • The Eatwell Guide. Public Health England. www.gov.uk, last updated September 2018
    • Healthy eating factsheet. British Dietetic Association. www.bda.uk.com, published August 2020
    • McCLernon FJ, Westman EC, Rose JE, et al. The effects of foods, beverages, and other factors on cigarette palatability. Nicotine Tob Res 2007; 9(4):505–10. doi: 10.1080/14622200701243177.

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