Some take the proper precautions against attacks. But others may not take asthma seriously enough until it's too late.
Early Show Medical Correspondent Dr. Emily Senay says asthma affects an estimated 17 million people in this country, and it can be deadly — killing 5,000 people annually.
It is a serious chronic lung condition that is triggered by irritants in the air. The environment causes the airways in the lungs to constrict and restrict the ability to breathe.
Many of the symptoms can be mild and people who have asthma may not seek attention until a severe attack occurs.
The American Lung Association says nearly half the U.S. population, more than 137 million people, lives in areas where the air quality is unhealthy.
To help solve the problem of awareness, throughout the month of May, the American College of Allergy, Asthma and Immunology will be offering free screenings for asthma at 300 locations around the country.
Since 1997, about 61,000 children and adults have taken advantage of the program. And, Dr. Senay says, it's useful for people to get the appropriate treatment after they discover they have asthma.
The screening involves filling out a questionnaire and taking a very simple breathing test where you're asked to breathe forcefully into a tube. If it looks like you might be at risk, you are referred to a doctor or asthma specialist for diagnosis and possible treatment.
The warning signs of asthma are shortness of breath, coughing, tightness in the chest and wheezing.
Dr. Senay says once you know you have asthma, you can treat it and avoid the things that trigger it.
Asthma can be triggered by a variety of irritants, such as smoking, pollen, pet dander, dust, some drug and food additives, viral respiratory infections, exercise and, of course, pollutants in the air from cars and industry.