Why is it that nasal breathing can be so much more beneficial to us than mouth breathing?
The nose has a number of features designed to bring cold dry outside air to a more acceptable condition before it enters the lungs. The mouth, however, is not intended to condition atmospheric air – it is merely for talking, eating and drinking. Air that is drawn in through the nose passes along turbinates and spends a longer period of time in the body. This serves to warm the inhaled air far more effectively than drawing it in through the mouth.
Air is ﬁltered by the turbinates and tiny hair-like structures that work to prevent pollen, dust and bacteria from entering the lungs. The sticky mucus blanket within the nose traps a signiﬁcant proportion of all the bacteria and allergens contained in air. On any one day, a person with asthma may inhale from 10,000 to 20,000 litres of air laden with foreign particles including many triggers. Whereas the nose can remove these deposited particles within ﬁfteen minutes, it takes 60–120 days for them to be removed from the small air sacs (alveolus) within the lungs.
Lungs require a warm moist environment and therefore it is imperative that the air drawn into the lungs meets this condition. The nose humidiﬁes inhaled air by increasing moisture content. A sign of good health is a moist nose while a dry nose can be a sign of dehydration. Take a moment now to think about a dog. Why a dog? Well, it’s common knowledge that when Fido’s nose is cool and moist, he’s most likely to be healthy, but when his nose is dry and hot, his owner is probably facing a trip to the vet!
It is just as important to breathe out through the nose as it is to breathe in through it, despite a common conviction, particularly among sporting professionals, to the contrary. By breathing out through the nose, part of the moisture contained in the exhaled air is retained, thus reducing moisture loss. Breathing out through the mouth results in a greater loss of carbon dioxide and may lead to dehydration. This can be observed by breathing onto a pane of glass and then checking the residue of moisture left.
Nasal breathing helps to regulate volume. All mouth breathers overbreathe and as a result suffer some symptoms of hyperventilation. The nose is a smaller channel to breathe through, and therefore it helps to reduce the volume of air as there is about ﬁfty per cent more resistance. It is possible to overbreathe through the nose but to a lesser extent.
Western research has concluded that the volume of air passing through the lungs of a person with asthma is usually between two and four times the norm.1,2,3 From this it is possible to deduct that the quantity of allergens inhaled by a person with asthma is far greater than that of a person with healthy breathing. By switching to nasal breathing and reducing the volume of air taken in, the quantity of the allergens inhaled will be dramatically reduced, resulting in less exposure to triggers.
Some people will instinctively hold their breath when- ever they come across a trigger, and this is a good idea. For example, if you are walking in the street and a bus emitting a large volume of fumes passes by, just breathe out, and try to hold your breath until you have walked away from the pollution. When you recommence breathing, reduce the volume so that the amount of polluted air entering the airways will be reduced.
A partially blocked nose is common with nasal breathing, one nostril will be partially blocked while the other is free to work. Check to see which of your nostrils is blocked by placing your ﬁnger over one nostril and breathing through the other; then repeat using the other nostril. You will ﬁnd that after three or four hours the blocked nostril will usually clear and the previously clear nostril will become blocked. This is a natural pattern which enables one nostril to rest at a time. During physical activity such as walking or light jogging, both nostrils will open up to allow more air into the body. When lying down at night, usually the lower nostril will be blocked and the upper nostril clear.
The importance of breathing through the nose tends to receive very little attention from the medical profession. It seems to be accepted without question that some people will breathe through the mouth and others through the nose. However, breathing through the mouth is detrimental to your health and this is emphasised to all patients who learn breath retraining. Mouth breathers have generally poorer health and may go through life with an uncomfortable and permanently blocked nose. Furthermore, mouth breathers have a higher incidence of cavities and gum disease than those who breathe through their nose.
It is vital to remember to breathe through the nose at all times and parents should also explain the importance of nasal breathing to their children. Parents will generally be the best judges of how to explain things but to help the child understand the importance of breathing through their nose, it might be helpful to explain to them the following way, using a little girl called Emily as our example:
The air that we breathe is not always clean. It can contain a large amount of dirt particles with germs, smoke and bacteria too small to be seen. The nose has tiny ﬁlters that clean this air before it goes into the body. If the air sneaks in through the mouth, we’re sucking in dirty air. This is not good at the best of times but is particularly so if a child like you or an adult like me has an asthma problem.
Whenever the child sees or smells dirty air, get her to hold her breath and walk away from it. Explain that the less dirty air she breathes in, the less difﬁculty she will have with her asthma. Air that sneaks in through the mouth is cold and dry and the body doesn’t really like that. Air that comes in through the nose is warm and moist and is much better for the body. Ask Emily whether she would prefer to be warm (but not too warm) or very cold. She will hopefully answer that she prefers to be warm. Then explain that the body prefers warm air too but it can only get this nice warm air by breathing through the nose. If she tells you that she prefers to be cold then I’m afraid you’re on your own explaining this one!