The nose is an olfactory organ and also a pathway for air entering the body, where it is warmed, filtered and moistened before passing into the lungs. The external nose leads to the nasal cavity, which has a mucous membrane with olfactory (smell) cells.

When the lungs try to throw out the excessive moisture present within, there is a reaction that leads to sneezing, nose block or allergic rhinitis. The lungs try hard to purify the system at their own level.