Smoking and Asthma

What is the link between smoking and asthma?
Smoke from cigars, cigarettes and pipes harms your body in many ways, but it is especially harmful to the respiratory system. The airways in a person with asthma are very sensitive and can react to many things, or "triggers." Coming into contact with these triggers often produces asthma symptoms. Tobacco smoke is a powerful asthma trigger.

Why is tobacco smoke so harmful?
When a person inhales tobacco smoke, irritating substances settle in the moist lining of the airways and can set off asthma episodes. Often, people with asthma who smoke keep their lungs in a constant state of poor asthma control and have ongoing asthma symptoms.

Tobacco smoke also damages tiny hair-like projections in the airways called "cilia." Normally, cilia sweep dust and mucus out of the airways. Cigarette smoke damages cilia so they are unable to work. Cigarette smoke also causes the lungs to make more mucus than normal. As a result, when cilia don't work, mucus and other irritating substances build up in the airways.

Tobacco smoke also contains many cancer-causing substances ("carcinogens," such as tar). These substances deposit in the lungs and can cause lung diseases such as lung cancer and emphysema.

Figure to the left shows a  healthy respiratory system showing the airways and lung. The bronchial tubes are the airways that branch into the lungs.

What is second-hand smoke and is it harmful?
Second-hand smoke is the combination of smoke from a burning cigarette and smoke exhaled by a smoker. Inhaling second-hand smoke, (also called passive smoke or environmental tobacco smoke), from another person's smoking may be even more harmful than smoking yourself. The smoke that burns off the end of a cigar or cigarette contains more harmful substances (tar, carbon monoxide, nicotine and others) than the smoke inhaled by the smoker.

Adults and children who live with a smoker are more likely to develop respiratory illnesses. Children are especially at risk because their lungs are smaller and still developing. Exposure to second-hand smoke can lead to decreased lung function and symptoms of airway inflammation such as cough, wheeze, and increased mucus production, especially in children.

Children with asthma are especially sensitive to second-hand smoke. They are more likely to develop asthma symptoms when exposed to second-hand smoke. They are also more likely to develop lung and sinus infections. These infections can make asthma symptoms worse and more difficult to control.

Ways to reduce exposure to smoke
If you smoke, quit for yourself and your children. If your spouse or other family members smoke, help them understand the dangers of smoking and encourage them to quit. Quitting is not always easy. There are many programs and methods to help you quit smoking. Ask your doctor to help you find the method that is best for you.

  • Do not allow smoking in your home or your car.
  • Do not permit your child's caregiver to smoke.
  • Avoid restaurants and public places that permit smoking.

Can smoking harm my unborn child?
Smoking harms the mother and her unborn child in many ways. Nicotine, the addictive substance in tobacco products, is carried through the bloodstream of the mother and goes directly to the baby. Children of mothers who smoked during pregnancy are more likely to have respiratory problems and are ten times more likely to develop asthma. Smoking during pregnancy has also been linked with low-weight newborns, premature births, and sudden infant death syndrome.

How can I quit smoking?

  • Hide your matches, lighters, and ashtrays.
  • Whenever you get the urge to smoke, take a deep breath and hold it for five to ten seconds.
  • Donít let others smoke in your home.
  • Keep finger foods, like carrot sticks, handy. Or, chew gum when you get the urge to smoke.
  • Stay active to keep your mind off smoking. Go for walks or read a book.
  • Join a support group or smoking cessation class.
  • Talk to your doctor about nicotine replacement aids (gum, patch) which can help when you are trying to quit.

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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. For additional written health information, please contact the Health Information Center at the Cleveland Clinic (216) 444-3771 or toll-free (800) 223-2273 extension 43771 or visit www.clevelandclinic.org/health/.

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