There are two common mistakes that people make when mixing the solution to use for a nasal rinse. The first is to make the solution with a saline content that is too high. This is called a hypertonic solution. The other common problem is for people to use mixture that has too low of a saline content. This is called a hypotonic solution.
The purpose of the nasal rinse or nasal lavage is to flush out the sinus cavities of any foreign material that could be an irritant. Anything in the nasal passages that does not belong there, such as pollen, or dust, can irritate the nasal passages and cause inflammation or swelling. In addition to swelling, the lining of the sinus cavities will produce mucus to surround the foreign matter to help protect the tissue in the sinuses. The inflammation and the mucus are the common cause of a stuffed up nose after being exposed to those foreign matters (ie: dust) which can be trapped in the sinus passages. Using a neti pot or a nasal rinse will flush that material out.
To properly use a nasal rinse, the solution should be mixed with a saline content that exactly matches that of one's nasal lining. If the solution is mixed with too much saline it will further irritate the nasal wall during the flush. Some people use a mix that has a higher saline content in the hopes that the saltiness will help dry out their sinus passages. While it is true that a higher salt content will draw out moisture from the nasal lining, reducing the swelling, the problem is that the saline also irritates the nasal passage even further, which can result in even more inflammation.
Conversely, using a hypotonic solution, one with too little saline, while it will not irritate the nasal passage, will allow the sinus wall to absorb some of the fluid from the rinse, which causes further swelling.
The best solution is an isotonic solution, which is mixed to the exact ratio of the saline content of your sinus passages. In addition to the right saltiness, some pre-made solutions are adjusted to the right pH to further avoid hurting the sinuses. When properly mixed, and at the right temperature, one may not even feel the nasal flush as the water moves through the passages. Even though we have all experienced the discomfort of having water flushed up our nose, when a nasal rinse is done properly, with the right temperature and the right saline balance there is no discomfort at all.
