Patients come to see me for various issues: stress, eczema, acute or chronic pain, digestive issues, insomnia, depression, anxiety, autoimmune diseases, menopause, asthma, fatigue, migraines, allergies -- the list goes on and on. With that being said, there is one common issue I have noticed during my internship with American patients. Most of them don't know how to breathe. What? Yes...you read that correctly. You say, "Well if that was the case, they wouldn't be alive!" Not true.
You might be able to breathe and get oxygen IN your body, while exhaling CO2, but if you are not doing it efficiently, your body will not operate optimally -- causing or exacerbating issues such as: headache, fatigue, GERD, indigestion, delayed digestion, insomnia, gas, bloating, anxiety, problems with memory, memory loss, or concentration. Breathing is essential to our survival and to our good health. We can live more than 50 days without food and about 7 days without water. But, without oxygen we cannot survive more than about 5 minutes.
In Traditional Chinese Medicine (TCM) theory, the lungs function to govern Qi and respiration. They disperse or move the Qi through the entire body via the channels and their collaterals. The Lungs cause the Qi to descend to the lower part of the body, activating and fueling vital physiological functions associated with digestion and the formation of blood. They also rule the surface of the body and the Wei Qi or protective Qi that moves just below the surface of the skin. Wei Qi forms a protective barrier to the invasion of the body by external pathogenic agents. In Western medicine, this kind of qi relates to the "immune system," however in TCM, the idea has a much broader meaning.
"Qi" can best be translated into English as a "life force." The closest translation describing Qi function into Western medicine might be "chemical reactions" that take place during cellular respiration, as well as activation andtransmissions across the nervous system and throughout the circulatory system. Blood chemistry will also affect the reactions in the body in order to move blood and help with organ function (i.e. as in the conduction system of the heart, where the blood moves around the body mainly through the beating of the heart caused by the electrical impulses of the SA node. Simply put, there are two main pathways, one is the pulmonary circuit that brings blood that has more carbon dioxide (deoxygenated) to the lungs to pick up oxygen, and the other is the systemic circuit (oxygenated) to all the rest of the body tissues). This movement and conduction of energy through the body is known as "Qi." Each organ system has it's own "qi" that is ultimately interconnected through complex channels of blood vessels, nerve clusters, the nervous system (afferent sensory neurons and efferent motor neuron tracks) andinter-cellular processes that enables each organ system to manifest and utilize energy.
In TCM, it is said that "Blood is the mother of Qi." Qi and Blood must work together for proper balance and bodily functions. Just like blood carries oxygen to the cells in need, the oxygen cannot move from cell to cell without energy. In Chinese medicine this "energy" is "qi."
In more modern scientific terms, the breath is the method that the body uses to draw oxygen into the blood for transportation to the cells where it provides the biochemical spark for cellular metabolism. - Bill Helm, "Qi Gong Health Exercises" 
Without proper body mechanics and the correct use of the diaphragm, cells, tissues and organ systems can be starved from the nutrients and oxygen needed, eventually causing some of the aforementioned symptoms and diseases. Proper breathing, on-the-other-hand, can benefit you in the following ways:
releases gases that are the waste products from metabolism
regulates the acid-alkaline balance of the blood stream
helps regulate water balance in the body
uses muscles which facilitate the flow of lymph through the lymphatic system
activates and massages the organs of digestion and elimination
lower blood pressure
raise blood pressure that is too low (*depending on which breathing techniques are utilized)
Various types of breathing will affect the body in different ways. Abdominal diaphragmatic breathing will lower blood pressure, activate peristalsis, and increase the venous return of deoxygenated blood. The increased circulation of blood raises the over all oxygen level of the blood. It also draws the Qi down into the lower part of the body which helps to relax the mind. Focused lower belly breathing will also strengthen the kidneys and the Ming Men Fire (the Kidneys in TCM theory are the activating yang element fro the spleen and lungs, thereby activating the digestive and respiratory systems).
Conversely, active breathing that is focused in the upper chest will increase blood pressure and stimulate the heart and lungs to move the blood and Qi more quickly and with greater force through the body. For person with low blood pressure and mental dullness due to sluggish circulation of blood and Qi, this can be very helpful.
Different systems use the breath in a variety of ways. The most common as listed in Qi Gong practices are: lower-abdominal, diaphragmatic or "Post-Natal Breathing"; reverse, lower-abdominal or "Pre-Natal Breathing" and alternating cycles of longer-shorter, inhale-exhale movements .
"Post-Natal Breathing" is often called "Natural Breathing" or "Baby Breathing". When inhaling, the lower abdomen protrudes and the abdominal muscles are relaxed. Upon exhaling, the lower abdomen moves towards the center of the body as the diaphragm releases and the intra-abdominal are relaxed. Upon exhaling, the lower abdomen moves towards the center of the body as the diaphragm releases and the intra-abdominal pressure is released. There are even breathing techniques to help with low libido, by Yang breathing techniques (increasing blood flow to the genitalia).
Alternating cycles of longer-shorter duration of inhale-exhale movements focus upon the duration of the cycles of inhaling-exhaling rather than the mechanics of breathing. By increasing the length of the inhale or exhale, or holding of either, different effects are produced. A long exhale cycle will decrease CO2 and other toxic gas levels and decrease blood pressure. Holding the inhale or the exhale or space between will concentrate the effects of either. Some systems will include muscular contraction of the abdomen and anus/genitals, or use either Pre-or Post-Natal Breathing mechanics to strengthen the desired effect.
The concept of cultivation, a gradual growth due to consistent, intentional activity is extremely important. This is especially important in the area of breathing exercises since they are the quickest acting and can produce the strongest initial response of any of the principles of Qi Gong. -Bill Helm - Qi Gong Health Exercises
Posture and body mechanics also play an important role in breathing and the body's ability to take in oxygen and expel waste. Posture or the literal physical position of the body plays a very important role in the functioning of all aspects of psychological and physiological processes.
The Chinese were not alone in recognizing the importance of the spine in the health of human beings. From the sages of Yoga, to Native American shamans, to current day chiropractic doctors, they all understood and understand the crucial importance of a healthy, erect spine. Even my own mother would yell at me and tell me to "sit up straight and stop slouching at the table!" Little did she know, that there were more benefits to good posture than just looking pretty. My little Native Mama prepared me in SO many ways for my current profession and life in general -- even in the little things. :)
To see how slouching or bad posture affects breathing, try this little experiment. Sit up straight, open your mouth, and speak the sound "ah" continuously. Now, slowly slouch forward while continuing to say "ah." Keep saying "ah" then lean back up, sitting erect with your back straight again. Do you see, feel and hear the difference? This was a technique I once used with my vocal students when I taught voice lessons years ago. In voice projection, good posture is very important. Learning to use the muscles of the abdomen as well as controlling the diaphragm, also improved vocal projection. Constriction of these muscles (including the vocal "chords") would inhibit ultimate performance for the performer. Slouching not only reduces the amount of oxygen one can get IN, but also constricts the amount of CO2 and waste products that can go OUT!
Breathe Deeply to Activate Vagus Nerve
(article below by Stanley Guan)
There is a new body of research in Western medicine, that shows that all of the breathing disorders, from asthma to tuberculosis, from emphysema to interstitial lung diseases, have been linked with an overactive immune system. The immune system is not the only system to benefit from proper breathing. The brain benefits as well. Research from Japan shows that during relaxed abdominal breathing, brain waves also show a pattern of relaxation. Finally, heart rate variability (HRV) has been studied extensively. Poor HRV has been linked with increased mortality after heart attack, and has also been shown to be linked with depression, anger, and anxiety. Research has found that proper breathing can improve HRV and reduce immune activation.
The bottom line: when we consciously and mindfully focus on our breathing, a rhythmic pattern of healthy heart rate variability and healthy immune function result. - Stanley Guan
And that means a longer and healthier life . For cancer patients, you can also use proper breathing to reduce pain.
Three Types of Breathing
As Dr. Liponis  describes, there are three types of breathing:
Clavicular breathing — A breath that comes from high up in the shoulders and collarbones
Chest breathing — A breath that comes from the centers of the chest
Abdominal breathing — A breath that comes from the abdomen
The first breathing pattern uses the collarbone (i.e. the clavicle) to help move air. You see it most often in people who are feeling panicked, or who truly are struggling for breath, as those with emphysema often do. Clavicular breathing is the most abnormal form of breathing. It occurs with serious breathing impairment or during extreme stress—such as in a panic attack.
The second breathing pattern is the most common kind (and one I see in a lot of my patients). Your chest and lungs will be expanding, but the expansion is restricted by tension and tightness in the muscles around the abdomen and ribs. This causes the chest to expand mainly upward, with less airflow and more rapid respiration.
The third kind of breath comes from the abdomen and uses diaphragm. When the diaphragm contracts, your lungs expand, pulling air in through your mouth like bellows. When you breathe from your abdomen, your belly will expand and move out with each inhalation. Your chest will rise slightly, but not nearly as much as with chest breathing; your abdomen is doing all the moving.
Doing abdominal breathing, you can activate vagus nerve and trigger a relaxation response. The relaxation response, which is the opposite of the stress response, is necessary for your body to heal, repair, and renew.
What's Vagus Nerve?
Your body's levels of stress hormones are regulated by the autonomic nervous system (ANS) . The ANS has two components that balance each other, the sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS).
The SNS turns up your nervous system. It helps us handle what we perceive to be emergencies and is in charge of the flight-or-fight response.
The PNS turns down the nervous system and helps us to be calm. It promotes relaxation, rest, sleep, and drowsiness by slowing our heart rate, slowing our breathing, constricts the pupils of our eyes, increases the production of saliva in our mouth, and so forth.
The vagus nerve is the nerve that comes from the brain and controls theparasympathetic nervous system, which controls your relaxation response. And this nervous system uses the neurotransmitter, acetylcholine. If your brain cannot communicate with your diaphragm via the release of acetylcholine from the vagus nerve (for example, impaired by botulinum toxin), then you will stop breathing and die.
Acetylcholine is responsible for learning and memory. It is also calming and relaxing, which is used by vagus nerve to send messages of peace and relaxation throughout your body. New research has found that acetylcholine is a major brake on inflammation in the body . In other words, stimulating your vagus nerve sends acetylcholine throughout your body, not only relaxing you but also turning down the fires of inflammation which is related to the negative effects from stress.
Exciting new research has also linked the vagus nerve to improved neurogenesis, increased BDNF output (brain-derived neurotrophic factor is like super fertilizer for your brain cells) and repair of brain tissue, and to actual regeneration throughout the body. For example, Theise et al.  have found that stems cells are directly connected to the vagus nerve. Activating the vagus nerve can stimulate stem cells to produce new cells and repair and rebuild your own organs.
There are many ways to activate the vagus nerve and turn on the relaxation response. When you take a deep breath and relax and expand your diaphragm, your vagus system is stimulated, you instantly turn on the parasympathetic nervous system, your cortisol levels are reduced, and your brain heals .
How to Activate the Vagus Nerve on Your Own
To practice deep breathing, inhale through your nose and exhale through your mouth. Remember to:
Breathe more slowly.
Breathe more deeply, from the belly.
Exhale longer than you inhale.
You can proceed as follows: take a breath into your belly (i.e. expanding your diaphragm) to the count of five, pause for a second, then breathe out slowly through a small hole in your mouth. While at rest most people take about 10 to 14 breaths per minute. Ideally, reduce your breathing to 5 to 7 times per minute. Exhaling through your mouth instead of nose makes your breathing a conscious process, not a subconscious one.
As you do this, your muscles will relax, dropping your worries and anxieties. The oxygen supply to your body's cells increases and this helps produce endorphins, the body's feel-good hormones. Tibetan monks have been practicing this to modulate the effects of stress for decades. They don't practice these ancient techniques to improve their memory, fight depression, lower blood pressure, or heart rate, or boost their immune systems, although all of those happen.
Using Breathing to Reduce Pain
For cancer patients, you can learn to use breathing exercises to shift your focus away from pain. The human mind processes one thing at a time. If you focus on the rhythm of your breathing, you're not focused on the pain. The moment we anticipate pain, most of us tend to stop breathing and hold our breath. Breath holding activates the fight/flight/freeze response, it tends to increase the sensation of pain, stiffness, anxiety, or fear. Whenever you anticipate pain—for example, when getting an IV inserted or having blood drawn, exhale instead of holding breath. (end of Stanley Guan article).
So as I see my hardworking patients, many times I see them rushing in to the office. Knowing that their day has most likely been filled with things they have to do (or dreading the things they have YET to do), I like to let them sit for a while before I get them on my table. I want to see them settle in to more calm surroundings, as their senses subconsciously say to them, "you can relax now -- this time is scheduled for YOU."
I know they have many obligations to family, friends, bosses, spouses, partners, clients...you name it. When do they have time for themselves? I have noticed that many Americans seem to have just forgotten how to breathe or they never really knew how to in the first place. Many spiritual traditions tout the benefits of just "being still" to take a break. There are many good reasons for this! Do yourself a favor -- if you can't make it in to my office to treat yourself to some pampering and good health for 60 minutes, at least take the time to breathe deeply...intently...consciously...for 10 minutes a day. Put this practice into your daily schedule. Your loved ones will thank you later as you become more calm and possibly more productive. If you do just this one thing, you will notice a change in your overall health. It's a promise! Be well.
"Qi Gong Health Exercises" by Bill Helm
Pavlov, V.A., and K.J. Tracey. 2005. The cholinergic anti-inflammatory pathway. Brain, Behavior and Immunity 19 (6):493-99.
Ultra Longevity by Mark Liponis, MD.
Theise, N.D., and R. Harris. 2006. Postmodern biology:(adult) (stem) cells are plastic, stochastic, complex, and uncertain. Handbook Exp Pharmacology (174):389-408.
Your Brain on Food by Gary L. Wenk
Fighting Cancer — A Nontoxic Approach to Treatment by Robert Gorter, MD, PhD and Erik Peper, PhD
Sloan, R. P., et al. 2007. RR interval variability is inversely related to inflammatory markers: The CARDIA study. Mol Med 13 (3-4):178-84.