The nose is the organ that “processes” the air we breathe before it reaches the lower respiratory tract (bronchi and lungs).
The functions of the nose and the lower airways are closely linked. The respiratory system is an integrated system, in which a disturbance in one part can have serious repercussions on the others.
This is why unimpaired nose breathing is important for keeping the bronchi and the lungs healthy.
Nasal congestion is a problem which should be dealt with quickly. But it is important not to use aggressive substances, since these can damage the delicate mucous membranes of the airways.