Your case of the sniffles isn't just annoying and gross. It adds up to a cost of $5.8 billion dollars a year in attempts to clear a stuffy nose. This is extra frustrating for doctors, because it turns out that your nose isn't what's stuffed.

A lot of nasal congestion has seemed like an unfixable problem, at least mechanically. Somewhere between physics and biology, people feel like they're being smothered when they aren't. Part of this is the physics of the nose's built-in temperature-control system. There's are reasons why the inside of the nose is disgusting and wet. By passing through the nostrils, air will be brought closer to the temperature of the body. Cold air will be passed along passages with blood vessels that warm it up before it heads into the lungs at the core of the body. The body also has to deal with warm air. Warm air is often dry air, and warm dry air evaporates the moisture in the nostrils. This evaporated moisture takes heat with it, cooling the nose, and letting the air pass through the cooled nose before heading into the body.

Once the physics of the nose have been dealt with, it's time to kick it over to biology. Because the evaporation both cools the nose and clears it of moisture, increased coldness and increased dryness are associated with a clearer nose and an unobstructed airway. Since people who are sick understandably try to keep warm, and because they sit steaming in their own sweat, the increased humidity and heat may lead to them feeling like they're unable to breathe through their nose, even if they can. They're left with enough space to breathe through, but unable to shake the feeling that they're being suffocated. Doctors think some simple cooling and de-humidifying system might help people with congestion breathe easier, sleep better, and not end up with billions of combined dollars of medical care.

Via PLoS One.

Image: My China Connection.