Diabetes Type 2 and Smoking

What is Type 2 Diabetes?

Type 2 diabetes is an acquired illness – this means that a person can develop it over the course of their life. It happens when there is too much sugar in a person’s blood. This can be because:

  • Insulin (which is a hormone that control blood sugar) does not work properly, so the cells in the body do not respond to it
  • The pancreas (the part of the body that makes insulin) cannot produce enough insulin to cope with the amount of sugar in a person’s blood

Unfortunately, diabetes is an illness that can affect somebody for their entire life. Like any illness, many people have to make adjustments to their day-to-day life, whether that be via managing symptoms, changing their diet, taking medication, injecting insulin (if appropriate), or taking steps to ensure that they do not have periods of very low blood sugar.

Smoking Increases the Risk of Type 2 Diabetes

According to the FDA, smokers are thirty to forty percent more likely to develop type 2 diabetes 1. This is down to several mechanisms 2:

  • smoking causes inflammation, which can produce dangerous chemicals – that can cause damage to cells, and this has been attributed to the development of type 2 diabetes
  • smoking can cause increased fat around the stomach, which can increase the risk of cardiovascular disease and diabetes
  • smoking increases the amount of cortisol, the stress hormone, in the body – cortisol can increase the amount of sugar in the blood
  • smoking can reduce how effectively insulin works in the body, meaning the pancreas will need to produce more, which makes the cells less likely to respond to it

Smoking Worsens the Complications of Diabetes

Smoking causes problems with circulation, or how your blood flows around your body. This is because it can lead to the formation of plaques in the blood vessels. This is important as diabetes can also cause circulation issues due to high glucose levels, which damages blood vessels. The two of these risk factors combined can lead to a variety of issues 3, 4:

  • poor healing of wounds, such as cuts, bruises, and ulcers – this can increase the risk of infections developing and may cause a patient to require amputation
  • increase in the risk of a heart attack or stroke
  • issues with vision, due to retinopathy, which is caused when there is significant damage to the blood vessels of the eyes
  • severe damage to the kidneys due to inadequate blood flow
  • diabetic neuropathy, which is when the nerves are damaged due to diabetes, can be worsened with smoking – this can lead to a loss of sensation in the feet and legs

Smoking also makes the management of diabetes more difficult 2. Nicotine stops the cells from responding properly to insulin, which increases the amount of sugar that is in the blood. This means that diabetes sufferers who smoke will, in most cases, have to take higher doses of medications and insulin than their non-smoking counterparts in order to control their diabetes.

Quitting Smoking Eases Management of Type 2 Diabetes

As mentioned above, smoking can worsen diabetes and its complications. One of the ways that it does this is by making the cells less sensitive to insulin. This means that the cells do not respond to insulin. 

Normally, insulin tells the cells to take glucose from the blood to use for respiration and other cellular processes. However, when a person smokes, that message is disrupted because of the nicotine. As a result, the cells do not use the glucose in the blood. This means the blood sugar remains high – which causes the development and progression of diabetes and makes it more difficult to manage diabetes.

Quitting smoking may make diabetes more manageable as a patient will need to take less medicine to lower their blood sugar.

There are some unwanted side effects of quitting smoking, such as weight gain. This is because smoking reduces a person’s appetite. Furthermore, ex-smokers may turn to overeat to keep their hands occupied. However, most healthcare professionals agree that the benefits of quitting outweigh the risk of weight gain.

Tips on Quitting Smoking

Quitting smoking can be difficult and deciding to quit is a very big decision. However, it is a step in the right direction and that in itself is praiseworthy! There are several ways to increase the chances of quitting for good:

  • Use nicotine replacement therapies, such as patches or sprays
  • List the reasons that you want to quit and remember them when you get a craving
  • Keep yourself (and your hands!) busy with something else
  • Throw away your smoking paraphernalia
  • Remind yourself of the benefits of quitting
  • Identify your smoking triggers and try to avoid them
  • Exercise – this releases endorphins and keeps you busy which can help you quit
  • Have a plan in place if you are tempted to smoke
  • Join groups online or in person that can give you support if you need it


Diabetes is a serious, lifelong condition that can cause a person’s blood sugar to be too high. 

Smoking causes the development and progression of diabetes. This means that it makes the illness worse and can increase the risk of developing diabetes related complications. Such complications include circulation issues, diabetic neuropathy and retinopathy, and kidney problems. This is because it stops the cells from responding to insulin.

Thirty to forty percent of smokers develop diabetes. Quitting smoking, alongside other benefits, may reduce a person's diabetes risk, or help to make diabetes more manageable.


  1. Products C for T. Cigarette Smoking: A Risk Factor for Type 2 Diabetes. FDA [Internet]. 2021 Sep 21; Available from: https://www.fda.gov/tobacco-products/health-effects-tobacco-use/cigarette-smoking-risk-factor-type-2-diabetes#references
  2. HHS/CDC. Smoking and Diabetes [Internet]. 2014. Available from: https://www.cdc.gov/tobacco/data_statistics/sgr/50th-anniversary/pdfs/fs_smoking_diabetes_508.pdf
  3. Seery Conor. Diabetes and Smoking [Internet]. diabetes.co.uk. 2019. Available from: https://www.diabetes.co.uk/diabetes-and-smoking.html
  4. Smoking and Diabetes [Internet]. Diabetes My Way | Greater Manchester | Wigan | Tameside NHS. Available from: https://diabetesmyway.nhs.uk/resources/internal/smoking-and-diabetes

Aisha Hayat

Bachelor of Science - BS, Biomedical Sciences, General, University of Bristol

Aisha is a Biomedical Sciences graduate with an understanding about research techniques, the pharmacology of drugs and the pathophysiology of illnesses. She is currently working as a healthcare assistant and has experience of research being used in a clinical setting, as well as the process of diagnosing and treating illnesses.

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