Cigarettes in ashtray

Cigarette smoke

53% of people with asthma tell us that tobacco smoke affects their asthma.

Smoking – and breathing in other people's smoke – can trigger asthma symptoms or even an asthma attack.

It's not just the smoke from cigarettes that causes a problem. The smoke from cigars, pipes, hand-rolled cigarettes, and shisha can trigger symptoms too.

Second-hand smoke

Second-hand smoke is sometimes known as passive smoking.

It’s a combination of the smoke breathed out by the smoker, and the smoke coming out of the lit end of their cigarette. Both smokers, and non-smokers around them, breathe this in.

Most second-hand smoke comes from the tip of the cigarette. So even if someone is trying to blow their smoke away from you, you’ll still be exposed to smoke from the cigarette’s tip.

Even if you don’t smoke, breathing in someone else’s cigarette smoke is just as bad for you as for the smoker.

And not only can it quickly trigger symptoms, it can also make asthma worse over the long term by causing permanent damage to the lungs.

Babies and children are most at risk from second-hand smoke

Anyone with asthma is at risk. This is because the chemicals in tobacco smoke irritate the airways and the lungs and trigger asthma symptoms.

But babies and small children are most at risk because they take more smoke into their lungs than adults.

And because they're still growing, and their immune system isn't fully developed yet, they're at greater risk from the toxins given out in the smoke.

They’ll be more likely to have chest infections and wheezing and coughing. They’ll also be more likely to go on to develop asthma as they get older.

Cigarette smoke makes your asthma harder to manage

When you smoke, or breathe in smoke, the chemicals in cigarette smoke irritate and inflame the airways and lungs. It can make symptoms come on quite quickly.

Whether you’re a smoker, or someone who’s regularly around other people who smoke, you'll have more symptoms and need more medicines to keep on top of your asthma. If your asthma symptoms get worse, you're at risk of an asthma attack.

Even if you're not a smoker yourself, symptoms can come on quite quickly when you come into contact with someone else smoking.

"A few years back, I had a party and allowed people to smoke in my house. Two hours later I was in A&E because the cigarette smoke triggered a really bad asthma attack." Michael Keenan 

Cigarette smoke in enclosed places

You're most at risk of second-hand smoke triggering your asthma in small enclosed spaces such as in a room at home.  

This is because toxic pollutants are more highly concentrated in a small space.

Even opening a window won't make enough of a difference. Tobacco smoke hangs around in the environment and can stay in the room for several hours.

If you smoke another cigarette in the room it tops up the pollutants already there. As well as this, smoke can stick to clothes and soft furnishings.

Cigarette smoke in cars

Smoking in cars is of particular risk to children because, as it's such an enclosed space, smoke can stay in the air for up to two and a half hours.

That’s why in England, Wales and Scotland it’s illegal to smoke in a car, or any vehicle, with anyone under 18 in it.

The law is in place to protect children and young people from the dangers of second-hand smoke. The ban doesn't apply to e-cigarettes.

Is the vapour from e-cigarettes an asthma trigger too?

While e-cigarettes are not risk-free, recent reviews of the evidence suggests that they are significantly less harmful than cigarettes in the short-term – both for those who smoke them, and those who are around them.

Evidence also suggests e-cigarettes work well as a stop smoking tool, especially alongside stop smoking support.

But very little research has been done so far looking at the effects on non-smokers with asthma who are exposed to e-cigarette vapours.

But we do know that:

  • in our Annual Asthma Survey 14% of people with asthma told us that either using e-cigarettes, or being exposed to second-hand vaping, triggered their symptoms
  • the propylene glycol in e-cigarettes can trigger a dry cough in some people – which could lead to asthma symptoms
  • e-cigarettes have been banned from indoor use in other countries in Europe, such as France, Italy and Portugal.

Shisha pipes

Shisha smoking, also known as waterpipe tobacco smoking, or hookah, has all the same risks as tobacco smoke and is linked to the same diseases.

If you're around someone else smoking shisha it could trigger asthma symptoms.

Second-hand smoke from waterpipe smoking includes both the tobacco smoke and smoke from the fuel used to heat the tobacco, such as wood cinders, or charcoal.

The same amount of smoke can be inhaled during a typical hour-long session as from more than a hundred tobacco cigarettes.

5 ways to avoid cigarette smoke triggering your asthma or your child’s asthma

1. If you smoke, give up.

This is one of the most important things that you can do to improve your asthma and your general health, and the health of your family. Find out what support there is out there and how quitting can make a real difference to asthma symptoms.

2. Ask people to smoke outside

If you live with a smoker, or have guests who smoke, ask them to smoke well away from the door so the smoke doesn't drift into the house. Remember that even if people are smoking outside they'll be bringing particles in with them on their clothes.

3. Keep your home and your car smoke-free.

For children in particular there's no safe level of exposure to second-hand smoke.

4. Avoid vaping in enclosed spaces too. Until there’s further evidence, we can’t say for sure that people with asthma aren’t at risk from e-cigarette vapour.

5. Talk to your older children with asthma about the risks of taking up smoking, and the risks of cigarette smoke triggering their asthma symptoms.


Find advice on other kinds of smoke that can trigger asthma symptoms, such as woodburning stoves, bonfires and barbecues.  

Last updated September 2018

Next review due September 2021