Emphysema involves progressive damage to the alveoli (air sacs) in the lungs over time making it difficult to breathe. The tiny alveoli carry oxygen to the bloodstream.
Emphysema forms holes in the inner walls of the alveoli, weakening the air sacs and making it difficult for the lungs to take-in enough oxygen to deliver to the bloodstream.
Over time, emphysema also makes the airways less elastic, resulting in the alveoli collapsing and trapping oxygen in the lungs. So those with emphysema have difficulty exhaling air, which also means they have a difficulty inhaling, too.
According to the Centers for Disease Control and Prevention (CDC), 3.4 million adults have been diagnosed with emphysema. In 2013, 8,284 individuals died from emphysema.