A blocked nose is undeniably uncomfortable. Anyone who has ever had a cold can tell you that. But did you know that chronic nasal obstruction can have many negative effects on health? Here, we'll touch on several of the most significant health benefits of nasal breathing.
1) The nose cleans, warms and humidifies the air.
As air passes into and through the nasal cavity, it flows past the hairs within the nostrils, filtering out larger particles, then over and around the nasal turbinates - folds of tissue attached to the outer walls of the nasal cavity. The turbinates are coated with a thin blanket of mucus, which traps smaller particles and adds moisture to the air. The turbinate tissues also contain a rich network of blood vessels, which efficiently warms the air to near body temperature. Thus, breathing through the nose efficiently delivers clean, warm and moist air to the lungs, where oxygen is then easily absorbed into the bloodstream.
Breathing unfiltered, cold and dry air through the mouth is harsher to the lower respiratory tract, causing thicker mucus, throat clearing, and cough.
2) The nose improves oxygen uptake and delivery.
The nasal cavity increases the resistance of breathing. This may not sound like a good thing, but it actually improves oxygen uptake in the lungs as well oxygen delivery to the tissues in our body. The increased resistance during nasal breathing helps open additional alveoli in the lungs. Alveoli are the tiny sac-like spaces where oxygen is absorbed into the blood. The more alveoli that get filled with air during breathing, the higher the oxygen uptake.
Additionally, nasal breathing promotes proper use of the diaphragm. There are two ways your body can draw air into the lungs: either by contracting the diaphragm downward into the stomach, or by contracting the muscles in and around the rib cage to pull the chest upward and outward. Using the diaphragm results in deeper, fuller breaths. Expanding the chest results in shallower, less effective breathing. Take a moment and breathe through your mouth, then through your nose. You tend to use more of the chest breathing technique when mouth-breathing, and more of the proper diaphragm breathing technique when breathing through your nose.
Because of the inefficient mechanics associated with mouth-breathing, this also tends to cause over-breathing, also called hyperventilation. This is a bad thing because of what it does to carbon dioxide. CO2 is not just a waste product. We actually need a certain level of this gas in our system. For one, it helps regulate the acidity (pH) of our blood, which must be maintained within a narrow range for our organs to function. Secondly, it actually helps oxygen get to our tissues. Oxygen is carried through the blood attached to hemoglobin, the major protein in red blood cells. Carbon dioxide buildup in our tissues helps the hemoglobin "let go" of the oxygen to be delivered to tissues. If we blow off too much of the carbon dioxide by hyperventilation, we actually decrease the amount of oxygen getting to our tissues as well.
Yet another way the nose may help improve oxygen uptake is by mixing the air with a gas called nitric oxide. This gas is actually produced in the sinus cavities, then steadily leaks out into the nose and mixes into the air as we breathe. In the lungs, this gas helps to open the small air passages. It also causes dilation of the small blood vessels in the lungs, improving the transport of oxygen into the blood.
3) Nasal breathing activates the parasympathetic nervous system, relaxing the body.
The autonomic nervous system is composed of the sympathetic and parasympathetic systems. The relative balance of these two systems' activity has sweeping effects throughout the body. The nicknames for these systems are the "fight or flight" (sympathetic) and "rest and digest" (parasympathetic) systems. By activating the parasympathetic nervous system, nasal breathing can promote relaxation of the body, slowing of the heartrate, and even lowering of blood pressure.
4) Nasal breathing promotes dental and orthodontic health.
Mouth breathing dries the mucous membranes and gums, decreasing the amount of protective saliva, which leads to increased bacterial growth. This can cause cavities and decay, as well as bad breath.
Nasal breathing also promotes proper tongue positioning along the roof of the mouth. During mouth breathing, the tongue drops into the floor of the mouth and tends to protrude into and between the front teeth. This can lead to misalignment of the teeth, and can even lead to abnormal growth and development of the palate and midface in children.
5) Oh yeah, and the nose allows you to smell.
I saved the obvious one for the end, but nonetheless important. Nasal breathing brings scents in contact with the nerve endings in the upper nasal cavity that connect to the olfactory bulb, the specialized nerve that brings this information to the brain. The sense of smell has very close ties to emotions as well as memory. Think of those times a certain smell will immediately take you back to a certain positive (or negative) experience in your past. The sense of smell is also an important part of taste. Most of what we experience as taste is actually linked to smell.
If you have trouble breathing through your nose, schedule an appointment! We'll figure out what can be done to help.