Summary
Read the full fact sheet- Second-hand smoke is a trigger for people with asthma.
- People who smoke and who have asthma have worse asthma control and faster loss of lung function.
- Women who smoke during pregnancy are harming the development of their baby’s lungs.
- If you have asthma, avoid smoky places whenever possible.
On this page
People with asthma have sensitive airways inside their lungs. Certain ‘triggers’ can make these airways narrow.
If you have asthma, smoking can lead to more asthma symptoms, more frequent and more severe asthma flare-ups, worse asthma control and less benefit from some asthma medications. It can also restrict your level of activity and reduce your quality of life.
Smoking also damages your airways, leading to inflammation and faster loss of lung function. (Lung function is a measure of the amount of air that you can breathe in and out of your lungs, and how hard and fast you can breathe out.)
Within weeks to months, stopping smoking may
- improve lung function
- reduce asthma symptoms and use of asthma inhalers
- improve response to asthma treatment
- improve asthma control
- improve quality of life as it relates to asthma.
Smoking causes damage to airways
Your lungs are lined by tiny hairs called cilia. These move in a wave-like motion to sweep dust, pollens and other irritants out of your lungs. Cigarette smoke damages these tiny hairs.
This means your lungs will be less able to clean themselves, which can lead to mucus and toxic substances collecting in the lungs, increasing the risk of lung infection. Smoking can also damage the small airways and air sacs within the lungs, causing lung disease including emphysema.
As lung disease slowly worsens over time, it can limit airflow, causing shortness of breath. Quitting smoking reduces your risk of developing lung disease, and slows down any worsening of lung disease if you already have it.
Asthma and passive smoking
Breathing in other people’s cigarette smoke can be harmful to people with asthma, especially children. Second-hand cigarette smoke can:
- trigger an asthma flare-up
- increase the frequency of asthma flare-ups
- increase your need for asthma medication
- reduce your lung function.
Smoking during pregnancy affects your baby’s health
If a woman smokes when she is pregnant, the chemicals in the cigarette smoke are passed to the developing baby through the umbilical cord. The baby’s lungs can be affected, which increases the baby’s risk of having weaker lungs and developing wheezing symptoms early in life.
Smoking during pregnancy also causes many other problems, such as low birth weight and premature labour, and increases the risk of fetal death and stillbirth.
Second-hand smoke can cause asthma in children
Children exposed to second-hand smoke are more likely to develop asthma in childhood. Children with asthma who live in a smoky environment have more severe symptoms, suffer more frequent asthma flare-ups and have poorer lung function. They are more likely to be admitted to hospital due to asthma and to use asthma medications.
Children of people who smoke are more likely to develop chest infections and other illnesses. Viral chest infections in infancy increase the risk of developing asthma in childhood, especially among infants who are sensitised to allergens.
In Victoria, it is illegal to smoke in cars carrying children who are under 18 years of age.
Asthma and smoking – reducing risk
You can reduce the risk of worsening your asthma by avoiding cigarette smoke. Some suggestions include:
- Quit smoking.
- Make your home completely smoke free – ask guests not to smoke in your house.
- Avoid smoky places, such as outdoor areas of pubs, bars and cafes.
If you wish to use nicotine replacement therapy or quitting medications to stop smoking, talk to your doctor or pharmacist about which products are suitable for you.
These medications do not have the same health risks as vapes. If you are thinking about using an e-cigarette or vape to quit smoking, it is important to speak to your doctor or pharmacist about your options to quit smoking first.
Asthma and smoking – when you can’t avoid smoky places
If you can’t always keep away from smoky places, it is important to manage your asthma on a daily basis. If you need to take your reliever medication more than two times a week (excluding ‘before exercise’ medication), visit your doctor. Your asthma action plan might need to be adjusted.
Remember to take your reliever medication with you when you visit a smoky place.
Where to get help
- Your GP (doctor)
- The Royal Children's Hospital has produced a number of videos to help you better understand and manage your child's asthma.
- Asthma Australia Tel. 1800 278 462
- Call Quitline on 13 7848 or visit the Quit website.
- Asthma in Australia 2011: with a focus chapter on chronic obstructive pulmonary disease, 2011, Australian Centre for Asthma Monitoring, Australian Institute for Health and Welfare. AIHW Asthma Series no. 4. Cat. no. ACM 22.
- Sly PD, Kusel M, and Holt PG 2010 ‘Do early-life viral infections cause asthma?', The Journal of Allergy and Clinical Immunology, vol. 125, no. 6, pp.1202–1205.
- How tobacco smoke causes disease: the biology and behavioral basis for smoking-attributable disease: a report of the Surgeon General, US Department of Health and Human Services.
- The health consequences of smoking – 50 years of progress: a report of the Surgeon General, 2014, US Department of Health and Human Services.
- ‘Chapter 3 – The health effects of active smoking’, in EM Greenhalgh, MM Scollo and MH Winstanley (eds), Tobacco in Australia: Facts and issues, Cancer Council Victoria.
- Chapter 4 - The health effects of secondhand smoke, in Greenhalgh EM, Scollo MM, and Winstanley MH [editors]. Tobacco in Australia: Facts and issues. Melbourne: Cancer Council Victoria; 2017.
- The health consequences of involuntary exposure to tobacco smoke: a report of the Surgeon General, 2006, US Department of Health and Human Services.
- Tiotui AI et al. 2020, Impact of air pollution on asthma outcomes, International Journal of Environmental Research and Public Health, vol. 17, 6212
- Gautier C, Charpin D 2017 ‘Environmental triggers and avoidance in the management of asthma’, Journal of Asthma and Allergy, vol. 10, pp. 47–56.
- Australian Asthma Handbook, Version 2.2, 2022, National Asthma Council Australia.
- Vapes: Information for patients. Vaping Hub, Australian Government, Department of Health and Aged Care, Therapeutic Goods Administration.
- Public health consequences of e-cigarettes, 2018, National Academies of Sciences, Engineering, and Medicine, The National Academies Press, Washington, DC.