Secondhand Smoke: Impact on Asthma

Visit the Centers for Disease Control and Prevention website to see the references for this article and for more information about smoking and your health.

What Is Asthma?

Asthma is a disease that affects the lungs. Asthma is an ongoing condition, but asthma attacks occur when something irritates the lungs. An asthma attack happens in the body’s airways, which are the "tubes" that carry air into and out of the lungs. During an asthma attack, the walls of the airways in the lungs swell, and the airways narrow. Less air gets in and out of the lungs, and mucus from the lungs clogs up the airways even more. During an attack, a person may have coughing, chest tightness, wheezing, and difficulty breathing. In rare cases, asthma attacks lead to death.


How Common Is Asthma?

Asthma is the most common long-term disease of children, but adults can have asthma, too. The number of people diagnosed with asthma grew by 4.3 million from 2001 to 2009. In 2010, 8.2% (18.7 million) of U.S. adults had asthma and 9.4% (7 million) of U.S. children had asthma.4,5 In 2007, there were 17 million hospital physician office visits with asthma as the primary diagnosis.6 Asthma was linked to 3,388 deaths in 2009.


What Are the Risk Factors for Asthma?

No one knows why some people get asthma and others don’t, but if someone in a family has asthma, other family members are also more likely to have it. What is better known is what can trigger an asthma attack—these include particles or conditions that irritate the lungs.


Asthma triggers include:

• Tobacco smoke 
• Outdoor air pollution 
• Cockroaches and their droppings 
• Furry pets 
• Mold 
• Dust mites 
• Respiratory infections like a common cold 
• Strenuous physical exercise 
• Some medicines (e.g., aspirin, ibuprofen) 
• Certain weather, such as thunderstorms, high humidity, or cold temperatures 
• Some foods and food additives 
• Strong emotional states, like stress, which can lead to hyperventilation 

How Is Exposure to Secondhand Smoke Related to Asthma?

Secondhand smoke is a mixture of gases and fine particles that includes:

• Smoke from a burning cigarette, cigar, or pipe tip 
• Smoke that has been exhaled or breathed out by the person or people smoking 
• More than 7,000 chemicals, including hundreds that are toxic and about 70 that can cause cancer 

For children who have asthma, breathing secondhand smoke can trigger an attack. The attack can be severe enough to send a child to the hospital. In rare cases, an asthma attack is so severe that a child dies.


What Are the Signs and Symptoms of Asthma and Asthma Attacks?

Asthma causes repeated episodes (or attacks) of wheezing, breathlessness, chest tightness, and coughing, especially at night and in the early morning.


How Is Asthma Treated?

There is no cure for asthma. However, asthma can be controlled by knowing the warning signs of an attack and treating an attack early, staying away from things that trigger an attack, and following the advice of a doctor or other medical professional. Controlling asthma will —

• Reduce or eliminate symptoms such as wheezing or coughing Improve sleep 
• Reduce missed work or school 
• Improve the ability to be physically active 
• Reduce the chance of having to go to the hospital 

People with asthma do not all take the same medicine. Some take medicines that can be inhaled, or breathed in, and some take pills. Asthma medicines come in two types — quick-relief and long-term control. Quick-relief medicines control the symptoms of an asthma attack. If someone with asthma needs to use quick-relief medicines often, he or she might want to consult their health care provider to see if a different medicine is needed. Long-term control medicines help reduce the frequency and severity of attacks, and quick-relief medicines treat an attack once it starts. Many people use both types of medicines. Asthma medicines can have side effects, but most side effects are mild and soon go away. Health care providers can give their patients information about the side effects of each medicine.


How Can Asthma Attacks Be Prevented?

It is unknown how to prevent someone from developing asthma. It is easier to determine how to avoid things that trigger attacks in people who have asthma. Staying far away from tobacco smoke is one important way to avoid asthma attacks. Some other helpful tips are:

• Do not allow anyone to smoke anywhere in or near your home. Some of the smoke stays in the house even if people only smoke near an open window. 
• Do not allow anyone to smoke in the car, even with the windows down. No amount of secondhand smoke is safe. 
• Make sure children’s day care centers and schools are tobacco-free. For schools, a tobacco-free campus policy means no tobacco use or advertising on school property is allowed by anyone at any time. This includes off-campus school events. 
• If your state still allows smoking in public areas, look for restaurants and other places that do not allow smoking. “No-smoking sections” in the same restaurant with “smoking sections” do not protect adequately from secondhand smoke. 
• Teach children to stay away from secondhand smoke. Be a good role model by not smoking.