The science of the netti pot

[Zoopshine]

Someone asked about this before. I had limited time and wasn't able to post the response, and now I'm too lazy to look up the post so I'll answer it here.

The question was, why does solution drain out of my sinuses long after I've used a netti pot?

The answer has to do with three things - pressure, inflammation, and osmosis.

First, pressure. Even something as gentle and low-pressure as a netti pot still has more pressure going into your sinuses than the air you're breathing. That means that solution is going to go at a higher rate of pressure into all the nooks and crannies than air will. That means it will be able to push itself further into said nooks and crannies.

Now comes inflammation. Inflammation is the body's natural response to an irritant. In a nutshell, the local blood vessels will automatically contract, which creates pressure inside the vessels themselves and causes fluid to be expressed into the tissues. This causes one of the very things we turn to netti pots for in the first place - congestion, which is nothing more than excess fluid creating swelling in the tissues.

Finally, we have osmosis. Simply put, this is the passage of water through a membrane from an area of greater to lesser concentration. When we use a salt solution, such as the hypertonic solution in a netti pot, the salt concentration in the solution is higher than that in the tissues of the sinuses. Water doesn't like this, so it moves through the membrane of your tissues into the fluid and is then washed away. This property of water is why a hypertonic solution, or a high concentration of salt, is recommended for nasal congestion, while a isotonic solution, which has roughly the same amount of salt that is naturally present in human tissues, is used for moisturizing (when the salt level is the same in and out of the cell, the solution remains unchanged where it is, thus providing needed moisture). A hypotonic solution, such as pure water, should never be used unless for some reason you WANT to cause congestion because that's precisely what it will do. Water will move into your tissues and you'll find yourself with a very stuffy head.

So here is what is happening with your netti pot - the solution, being of higher pressure than air, is working its way into some tight spots. Your body responds with a slight increase in inflammation, which further narrows or may even close off those tight spots. Then after a time the solution is able to draw out that excess fluid of inflammation, re-opening the channels and the solution drains back out a few minutes later.

There are a couple of options here. The first is simply to wait - what goes up will eventually come down. After about five minutes, tilt your head forward and back, side to side, maybe even try lying flat on your back to help the solution drain. Your XPAP, being higher pressure than the air you typically breathe, can also help by pushing solution out of your sinus passages, so it may be worth popping it on for a moment or two.

One thing I must stress - never ever EVER use tap water for a netti rinse! Always use steam distilled, or, at the very least, boil your water and let it cool prior to using it for netti rinse.

http://www.cdc.gov/parasites/naegleria/ ... nsing.html