About six years ago, Barbara Hinkle, 67, of La Mesa, California, learned she had chronic obstructive pulmonary disease. Her COPD flare-ups grew increasingly frequent and severe, and in February she had a frightening episode. “I struggled one night, all night, and ended up calling 911 myself, because it felt like I wasn’t going to take another breath,” she says. “It was the scariest thing that ever happened to me in my life.”

COPD is a catch-all term for bronchitis, emphysema and in some cases, chronic asthma. All are associated with airflow obstruction, says Andrew Ries, a professor of family medicine and preventive medicine at the University of California–San Diego. While some patients have a lot of coughing and phlegm, breathlessness is the red-flag symptom. “Patients often first notice it with activities – they’re getting older, and they can’t keep up with people their own age on inclines or stairs,” Ries says. “They’re getting more shortness of breath, and their physical activities are getting diminished – and it’s more than just aging.”

There’s no cure for COPDs. The goal is to slow progression as much as possible to maintain quality of life and keep patients from getting worse.

“C” Is for Cigarettes

About 15 million Americans have been diagnosed with COPD, while millions more may have it without realizing it. It’s the third leading cause of death in the United States and a major cause of disability, according to the Centers for Disease Control and Prevention.

Heavy smoking is the common denominator. At least 80 percent of COPD patients are current or former smokers, usually with pack-a-day (or more) habits over many years. Many people struggling with COPD now were kids or teens when the landmark U.S. Surgeon General’s report on the health risks of smoking came out 50 years ago. Back then, smoking was still popular and becoming more so among women. ​ However, COPD is not always due to smoking. A genetic condition called alpha-1 antitrypsin deficiency – a lack of a lung-protective enzyme – puts people at higher risk for COPD, specifically, emphysema. 

Similar to lung cancer, death rates from COPD are declining – at least in men. From 1999 to 2010, death rates dropped from 57 men per 100,000 men to less than 48 per 100,000, according to the CDC . But rates for women increased slightly in the same period – from about 35 to 36 women per 100,000 women.

[Read: Why are Lung Cancer Rates and Deaths Plummeting?]

“O” Is for Oxygen

Tony Kanzia, 68, ​has COPD, which nudged him into retirement. After working in the automobile industry in the ​Chicago area for 35 years, ​he called it quits. “I couldn’t do my job anymore,” he says. “I couldn’t even walk out to the lot to show people the car; let alone go on a test drive – I needed my oxygen.”

He used to enjoy air travel but the planning – let alone the flights – all became too much. It involved calling the airline in advance and renting an oxygen tank, along with packing his pulse oximeter – a small device that lets people clip a probe on their finger or ear to show how well blood is saturated with oxygen. Kanzia recalls the last straw flight, when even a trip to the restroom became a hazard. To tolerate the expected minute or two without his oxygen, he did breathing exercises before leaving his seat. But when he exited the restroom, the service cart was blocking the aisle, and his oxygen saturation dropped as he waited. Flight attendants saw he was in distress and got him back in his seat. ​ 

Many COPD patients manage without oxygen therapy, or only use it as needed. Others with severe COPD rely more heavily on oxygen.

Jean Rommes, 70, a ​semi-retired consultant and COPD activist in West Des Moines, Iowa, still travels a lot – always with ​an oxygen tank. Her strategy is to “swallow her pride” and get help as needed to save precious energy. She flies via major airports and uses a wheelchair to get from one concourse to another, although she prefers going by an airport cart with other travelers.

Bunny Music, ​70, of Sussex, New Jersey, has used oxygen around the clock for 13 years. She uses liquid oxygen, which she finds easy to carry over her shoulder, rather than a cumbersome gas cylinder (the green tank on wheels). Oxygen​ concentrators are the third option, but Music says they’re heavy and hard to manage with a walker or cane, and “you can’t depend upon them if your electricity goes off.”