Nearly 1 in 10 Americans have asthma. Here's what causes it.
Asthma is one of the most common lung diseases in the world, affecting some 262 million people worldwide and causing more than 450,000 deaths annually, per the World Health Organization. While prevalence is likely higher due to the fact that asthma can go undiagnosed and untreated, nearly 1 in 10 adults living in the United States likely has the condition per the U.S. Centers for Disease Control and Prevention. It also affects "approximately 4.9 million children under 18 living in the country that have been currently diagnosed," says Dr. Deena Avner, a pediatric pulmonologist for the Atlantic Health System in New Jersey.
Here's what the lung condition is, what causes it, and how you can expect asthma to be treated if it's diagnosed in you or a loved one.
What is asthma?
Asthma is a lung condition that can make your airways swell, narrow, and fill with mucus. "This causes recurrent episodes of coughing, wheezing, and chest tightness," says Dr. Laura Conrad, director of the Pediatric Asthma Center at the Children’s Hospital at Montefiore in New York.
Depending on the severity of your asthma, such breathing difficulties can range from being a minor inconvenience to causing major disturbances in sleep quality, sport performance, missing work or school, and higher vulnerability to lung conditions - sometimes even becoming life-threatening. "Asthma can be episodic or chronic as it affects people differently with some people only having intermittent mild symptoms and other people having chronic severe symptoms," says Dr. Joshua Burkhardt, an allergy, asthma and immunology specialist at Revere Health in Utah.
One of the reasons the condition is often undiagnosed is because testing usually requires cooperation and effort on the part of the patient, "and most young children cannot perform needed testing," says Burkhardt. He says the most reliable test is known as a lung function testing - which is performed by breathing through a tube to measure the efficiency of air flow.
"There are other breathing tests which can be useful, including peak expiratory flow measurements and fractional exhaled nitric oxide testing," he adds, "and to help determine the type of inflammation, blood tests are often used as well."
What causes asthma?
While the exact cause of asthma is unknown, "certain genetic factors can increase the risk of developing the disease," says Avner. For example, she explains that if a parent has asthma, a child is three to six times more likely to have it as well. "Asthma is also more common in people with other allergic conditions, like eczema and hay fever," she adds. Early life vulnerability factors such as being born with a low birth weight or being born prematurely can affect lung development and raise the risk of asthma as well. "Early exposure to certain viral infections can also increase the risk of developing the condition," says Conrad.
Environmental factors such as air pollution and allergens like dust mites and molds can also increase one's risk. "Moreover, children and adults who are overweight or obese are at a higher risk of developing asthma," Avner adds.
If one has asthma, it's commonly triggered by exercise, cold air (or sudden temperature changes), acid reflux, respiratory infections (even the common cold), breathing in chemicals from smoke, cleaning solutions, air pollution, or fragrances, or experiencing anxiety or stress, says Burkhardt.
How is asthma treated?
Though there is no cure for asthma, Avner says there are key treatments available to help manage the condition. These commonly include inhaled medications such as steroids, "which reduce inflammation," and bronchodilators, "which help open the airways."
Burkhardt adds that for patients with allergic asthma or who have other allergic conditions, "allergen immunotherapy can also be beneficial."
It's also important to maintain a nutritious diet, keep a healthy weight, avoid known asthma triggers, "and to follow an asthma action plan developed with your doctor so you know when to use both preventative daily-controller medications and as-needed rescue medications," advises Conrad.
"Thankfully, asthma nowadays is a much more manageable disease with good outcomes than it used to be," offers Burkhardt. "But it does require persistence and lifelong treatment in many cases."
This article originally appeared on USA TODAY: What is asthma?
