Cigarette smoke is known to raise your risk of experiencing asthma symptoms and can be especially dangerous for children.

Even if you’re a smoker, it’s hard to pretend that you don’t know smoking is harmful to your health.

While various cities continue to make it harder to smoke by hiking the cost of cigarettes or carrying out citywide nonsmoking policies for indoor spaces, the reality is that people still smoke. No one is surprised to learn that regular smoking can lead to poor health outcomes that extend beyond respiratory problems.

But not everyone is aware that being exposed to cigarette smoke — even when you’re not a smoker — can be a problem. This goes beyond creating poor air quality and forcing others to inhale smoke. In particular, secondhand smoke exposure has been linked to asthma.

If you’re a smoker and you need another reason to quit, consider how your lifestyle choices might be affecting your loved ones’ health as well as your own.

The answer to this question can be tricky. Officially, tobacco smoke, or more specifically secondhand smoke, isn’t considered a known factor that causes asthma.

But for many people with asthma, smoke is a known trigger — or a substance that can encourage an asthma flare-up. Tobacco smoke contains more than 7,000 chemicals that can harm people, with roughly 70 that can encourage cancer.

Asthma is a complex health condition, and only very rarely can an official cause be determined.

It is recommended for everyone to limit their exposure to tobacco smoke. And the evidence shows that people with asthma are even more susceptible to poor health as a result. From more frequent asthma attacks (uncontrolled asthma) to frequent symptoms, there’s an easy case to be made to stay away from secondhand smoke — or, more importantly, to not smoke — if you have asthma.

Secondhand smoke and infants

While no connection to infantile asthma has been proven, infants born to parents who smoked (or who also live in smoking homes) are at a higher risk of experiencing sudden infant death syndrome (SIDS). Cigarette smoke exposure and co-sleeping with a smoker are considered major contributing factors.

Statistically, infants that die from SIDS tend to have more nicotine in their respiratory system.

Secondhand smoke and children

Cigarette smoke exposure may not cause asthma, but it can make the condition worse. In particular, research has shown that children with asthma that live in homes with parents that smoke tend to experience more frequent and severe flare-ups than children who have asthma and nonsmoking parents.

Likewise, hallmark asthma symptoms like wheezing and coughing are more common in children in smoking homes. Children exposed to cigarette smoke are also more likely to experience ear infections than those in nonsmoking environments.

Secondhand smoke and adults

Smoke exposure, whether you’re a smoker or around someone who smokes, still results in a higher risk of experiencing asthma flare-ups and worse symptoms. But adults are also more likely to experience other respiratory conditions as well.

Get involved!

There’s still a lot we don’t know about the exact causes of asthma and cigarette smoke’s role in its development. If you want to help researchers better understand this connection, you can check out to see what studies are currently looking for participants.

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Smoking and secondhand smoke in particular aren’t just associated with asthma. Secondhand smoke has also been specifically linked to chronic obstructive pulmonary disease (COPD) in adults.

A 2021 study conducted in Denmark reviewed 20,421 adults with a recorded history of secondhand smoke exposure. The average age of the participants was mid-50s. The cohorts were divided into three categories: lifelong secondhand smoke exposure, exposure only in adulthood, and exposure in childhood only.

Those with lifelong exposure tended to have higher rates of wheezing, cough, shortness of breath during activity, asthma, and COPD as compared with the other two groups. In short, they found that long-term exposure to secondhand smoke can greatly reduce your lung function.

Note that because the chemicals found in secondhand smoke are so toxic, people who are routinely exposed to it have a heightened risk of developing:

What’s thirdhand cigarette smoke?

Thirdhand smoke refers to residue left by tobacco smoke that sticks to surfaces. This can be just as dangerous as primary smoking and secondhand smoke exposure.

Similar to secondhand smoke, children are more susceptible to the health effects of thirdhand smoke. Likewise, the residue left from smoking can remain for up to 6 months even after a person quits smoking — which is what makes it so dangerous.

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Reversing the effects of secondhand smoke usually isn’t an option once the damage has occurred. Prevention is the best way to avoid experiencing damage related to this phenomenon.

You can learn more about controlling or reducing asthma symptoms with these Healthline resources:

If you’re a smoker, making a plan to quit smoking can protect your family and loved ones from poor health caused by secondhand smoke exposure.

Resources for quitting smoking

Although some people might be able to quit “cold turkey,” nicotine cravings can be strong. Along with having a supportive network that encourages you to take quitting smoking seriously, use essential resources to make quitting easier.

Many health insurance plans cover enrollment in quitting programs. You can also look into these free resources:

  • The U.S. government offers, an official resource with lists of organization numbers and websites.
  • Centers for Disease Control and Prevention (CDC): The CDC also hosts many resources to help you quit smoking at your pace.
  • Food and Drug Administration (FDA): The FDA has an approved list of medications like gums and patches that can help gradually reduce your nicotine dependence.
  • American Lung Association (ALA): The ALA also has a list of local and national resources outlined.

Consider asking a doctor or healthcare professional about local quitting programs in your community.

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Most people know that smoking can cause many health problems. But not everyone knows that secondhand smoke can be just as harmful.

While asthma is one of the most well-known respiratory conditions that can be triggered by secondhand smoke, other concerns like ear infections in children, SIDS in infants, and COPD in adults can develop as a result of exposure.

If you currently smoke, make a plan to quit to protect your loved ones. If you don’t smoke but spend time around smokers, make plans to protect your air quality.