Pulmonary physician Bruce L. Davidson MD, MPH, discusses aspiration during sleep with CNN.

Studies have shown that at least half of normal people — young, middle-aged, elderly — aspirate at night during sleep. By the end of a week, probably we all have. After taking a sleeping pill or a couple beers or shots — and sleeping more deeply — the chance of aspiration is even higher. And as we age, ordinary swallowing often becomes less well coordinated.

If you have lung damage from smoking, swallowing saliva, which we all do while we sleep, can deliver even more aspirated throat contents into the lungs. The amount of fluid aspirated during sleep is enough to cause pneumonia — in fact, it’s how most pneumonia occurs.

Get the full story at cnn.com