By the numbers
21,000: The number of Clark County adults with asthma in 2009.
18.7 million: The number of American adults with asthma in 2010.
7 million: The number of American kids with asthma in 2010.
12 million: The number of people who had an asthma attack in 2008.
3,388: The number of people who died from asthma in 2009.
$56 billion: The amount asthma costs each year.
For more and more people, the simple act of breathing is becoming complicated.
One in 12 people across the country — equal to about 25 million Americans — has asthma, and the numbers are increasing every year, according to the Centers for Disease Control and Prevention.
In 2001, about 7 percent of the U.S. population had asthma. In 2009 (the most recent data available), about 8 percent of the population had the chronic disease, according to the CDC.
During those eight years, the number of people diagnosed with asthma grew by 4.3 million, but, according to the CDC, the reason for the increase is unclear. Health officials do know, however, that people with asthma can control their symptoms and avoid asthma attacks by following an asthma-control plan.
Asthma is a chronic lung disease that causes the airways to swell and narrow, leading to wheezing, shortness of breath, chest tightness, and coughing. Asthma is caused by inflamed airways and bronchospasms, which are spasms of the smooth muscle in the airway, said Dr. Karen Kuryla, at Kaiser Permanente's Cascade Park Clinic.
"It's an atypical reaction to some sort of stress to the body," she said.
That stressor varies from person to person.
For some people, asthma is triggered by allergies, illness or cigarette smoke. Asthma can also run in families, and some people may develop asthma after continued occupational exposures, Kuryla said.
Just as stressors vary, so do the ages of people with the disease.
In 2010, about 7 million children had asthma, according to the CDC. Many children are diagnosed with asthma, only to grow out of the disease as they get older and their bodies develop resistance to triggers, Kuryla said.
People can also be diagnosed as teens, adults and seniors, but they are more likely to have the disease for their lifetime, she said.
"I can't say there's a total cure in adulthood," Kuryla said. "But they can do better, be stable and not have attacks."
An asthma attack occurs when the muscles surrounding the airways become tight and the lining of the air passage swells, reducing the amount of air passing by, according to the National Institutes of Health.
Avoiding known triggers is the easiest way to prevent asthma attacks, Kuryla said. For those who are overweight, dropping extra pounds can also help, she said. Paying attention to warning signs — such as coughing, slight wheezing and difficulty breathing — and taking medication as directed is also important, Kuryla said.
The most common type of asthma is exercise-induced asthma. With exercise-induced asthma, the airways become inflamed and the spasms begin 15 to 20 minutes after starting physical activity. Usually, Kuryla said, this type of asthma is treated by using a fast-acting inhaler (often called rescue inhalers), such as albuterol, about 20 minutes before exercising, Kuryla said.
People with mild asthma typically only use the fast-acting inhalers when they're experiencing symptoms. For people with more persistent asthma, a steroid maintenance inhaler might also be necessary, Kuryla said. And in extreme cases, which are rare, people may need to take oral steroids, she said.