By Dr. Mercola
A sigh is a long, deep breath, slowly inhaled and exhaled, which often occurs during times of stress, sadness, relief or exhaustion.
While you may consciously decide to sigh as a form of emotional expression, your body also sighs spontaneously every few minutes as a way to reinflate your alveoli, the tiny sacs in your lungs that help oxygen and carbon dioxide travel from your lungs to your bloodstream.1
You probably don't even notice your spontaneous sighs, but if you pay close enough attention you can easily pick them out. As The Seattle Times reported:2
"You can test this for yourself by lying down in a quiet room and paying close attention to your breathing. About once every five minutes you will notice that your body takes an inhalation, and just before the exhale, adds another inhalation on top of it."
Scientists Pinpoint How (and Why) Your Brain Controls Sighs
The extra inhalation that a spontaneous sigh provides serves an important purpose. It brings in twice the volume of air, which serves to pop open your alveoli.
Your lungs contain 500 million of the balloon-like sacs, which are the points where oxygen enters your bloodstream and carbon dioxide is removed.
When your alveoli collapse, a sigh is the only way to reinflate them. This likely explains why the average adult sighs involuntarily about 12 times every hour, according to Jack Feldman, Ph.D. a professor of neurobiology at UCLA.3
After years of research, Feldman and colleagues have highlighted the brain region where sighs originate and unraveled some of the mystery of how and why this reflex occurs. As reported by The Seattle Times:4
"Some years ago, a toxin found on the skin of South American frogs was found to induce rapid sighing when injected into brainstems of rats.
Later, two small populations of neurons that produce similar molecules were found near a region of the brain well known as the core of the body's breathing control center."
The latest study was conducted in rodents, which sigh up to 40 times an hour. Researchers revealed a "peptidergic sigh control circuit" in rodent brains and hope the discovery may one day be used to help those who sigh too little or too much (the latter may occur with anxiety disorders, for instance).
The researchers believe "these overlapping peptidergic pathways comprise the core of a sigh control circuit that integrates physiological and perhaps emotional input to transform normal breaths into sighs."5
Frequent Sighing Is a Sign of Dysfunctional Breathing
You probably don't give much thought to your breathing patterns or frequency of sighing, but if you've ever noticed frequent sighing, this is a classic sign of hyperventilation syndrome.
Chronic hyperventilation syndrome was initially documented during the American Civil War, at which time it was termed "irritable heart."
The term "hyperventilation syndrome" was coined in 1937, and shortly after it was discovered that you could reproduce the symptoms of this syndrome simply by taking 20 or 30 big breaths through your mouth within a span of one or two minutes.
As noted by Patrick McKeown, author of "The Oxygen Advantage: The Simple, Scientifically Proven Breathing Techniques for a Healthier, Slimmer, Faster, and Fitter You," once the habit of overbreathing is set in place, it tends to become and remain chronic.
To recover you typically need to use some sort of relearning technique, such as the one devised by Russian doctor Konstantin Buteyko. In 1957, Dr. Buteyko came up with the term "disease of deep breathing," having researched the health effects of excessive breathing for over a decade.
While still in medical training, one of his assignments included monitoring patients' breathing volume. And he noticed something of interest. The sicker the patient got, the heavier they breathed.
Common Signs of Inefficient Breathing
Later research has revealed that normal breathing volume is approximately four to six liters of air per minute during rest, equating to 10 to 12 breaths per minute.
Meanwhile, breathing volume for people with asthma tends to be around 13 to 15 liters per minute and those with sleep apnea breathe on average 10 to 15 liters per minute.
In short, asthmatics and those with sleep apnea breathe far too much — upwards of three times more than normal — and this dysfunctional breathing pattern is part of their disease profile.
According to Patrick, one of the leading teachers of the Buteyko Breathing Method, hyperventilation is defined as "breathing in excess of metabolic requirements of the body at that time."
There are a number of signs or symptoms that can alert you to the fact that you're not breathing as efficiently as you could. This includes:
Mouth breathing Upper chest breathing, with lots of visible movement with each breath Frequent sighing Noticeable or audible breathing during rest Taking large breaths prior to talking Erratic breathing Regular sniffing Yawning with big breaths Chronic rhinitis (nasal congestion and runny nose) Sleep apnea
Overbreathing Is Associated With Serious Health Problems
If you sigh frequently, it's a sign your body may not be receiving adequate oxygen distribution, hence your body is trying to compensate by bringing in more air to reinflate your lungs' alveoli.
While you might think taking a few deep breaths would accomplish this, if you're breathing too heavily you lose carbon dioxide, which causes the smooth muscles around your airways to constrict.
This creates a negative feedback loop that can lead to chronic hyperventilating and, potentially, exercise-induced asthma.6,7
If you take five or six big breaths in and out of your mouth, you can experience the problem with overbreathing first-hand, as most people will begin to experience some light-headedness or dizziness.
This occurs because you're eliminating too much carbon dioxide from your bloodstream, which causes your blood vessels to constrict — hence the light-headedness.
The heavier you breathe, the less oxygen that's actually delivered throughout your body due to lack of carbon dioxide, which causes your blood vessels to constrict.
The loss of carbon dioxide caused by heavy breathing also reduces blood flow to your heart, which in some unfortunate cases could lead to cardiac arrest or heart attack.
In fact, the repercussions of chronic overbreathing include cardiovascular, neurological, respiratory, muscular, gastrointestinal, and psychological effects, such as:
Heart palpitations Missed heart beats Tachycardia Sharp or atypical chest pain Angina Cold hands and feet Raynaud's Headache Capillary vasoconstriction Dizziness Feeling faint Paresthesias (numbness, tingling, and pins and needles) Shortness of breath, or chest tightness Irritable cough Muscle cramps, pain, and stiffness Anxiety, panic, and phobias Allergies Difficulty swallowing; globus (lump in the throat) Acid reflux, heartburn Gas, belching, bloating, and abdominal discomfort Weakness; exhaustion Impaired concentration and memory Disturbed sleep, including nightmares Emotional sweating
Abnormal Breathing Patterns Could Be Causing Your Health Symptoms
At first it might seem surprising that abnormal breathing could cause so many symptoms, but breathing is intricately involved in your psychological and physiological health. As noted in the book "Behavioral and Psychological Approaches to Breathing Disorders:8
"We start life with a breath, and the process continues automatically for the rest of our lives. Because breathing continues on its own, without our awareness, it does not necessarily mean that it is always functioning for optimum mental and physical health. The opposite is true often.
… Breathing affects our psychological and physiological states, while our psychological states affect the pattern of our breathing. For example, when anxious, we tend to hold our breath and speak at the end of inspiration in a high-pitched voice.
Depressed people tend to sigh and speak at the end of expiration in a low-toned voice. A child having a temper tantrum holds his or her breath until blue in the face.
Hyperventilation causes not only anxiety but also such a variety of symptoms that patients can go from one specialty department to another until a wise clinician spots the abnormal breathing pattern and the patient is successfully trained to shift from maladaptive to normal breathing behavior."
Why You Shouldn't Take Deep Breaths to Relieve Stress
Taking deep breaths is a widely circulated tool for stress relief. It's also what happens when you sigh, which tends to occur more often during stressful periods. However, according to Patrick, one of the most effective ways to address stress is actually to slow down your breathing.
Stress makes you breathe faster and promotes sighing, so to counteract or release stress, you need to do the opposite — breathe slower, softer, and make your breathing more regular. Ideally, your breathing should be so light, soft, and gentle "that the fine hairs within the nostrils remain motionless."
Importantly, make sure to breathe through your nose, not your mouth. According to the late Dr. Maurice Cottle, who founded the American Rhinologic Society in 1954, your nose performs at least 30 functions, all of which are important supplements to the roles played by the lungs, heart, and other organs.9
Part of the benefits of nose breathing is related to the fact that there is nitric oxide in your nose, and when you breathe gently and slowly through your nose you carry a small amount of this beneficial gas into your lungs.
Nitric oxide not only helps maintain homeostasis, or balance, within your body, it also helps to open your airways (bronchodilation), open your blood vessels (vasodilation), and has antibacterial properties that helps neutralize germs and bacteria.
Nose breathing also helps normalize your breathing volume. This is important because when you chronically overbreathe, the heavier breathing volume that's coming into your lungs can cause a disturbance of blood gasses, including the loss of carbon dioxide (CO2).
Why You Want to Avoid the Loss of Too Much Carbon Dioxide
As carbon dioxide levels lower, so too does the hydrogen ion leading to an excess of bicarbonate ions and a deficiency in hydrogen ions, which shifts the pH of your blood toward alkaline. Now, if your breathing exceeds what your body requires over a period of time, even as short as 24 hours, your body becomes conditioned to increase its breathing volume. This is one of the ways stress ends up having a chronic impact on your biology.
Moreover, if you're chronically overbreathing, it doesn't take much to push your body over the proverbial edge — even a minor emotional stressor can now provoke symptoms, be it a panic attack or heart-related problem, as overbreathing produces constriction of your arteries, thereby reducing blood flow to both brain and heart (as well as the rest of your body).
But the issue that triggered the attack was not the stressor itself; the main issue was the fact that you're chronically breathing too much. One traditional remedy for a panic attack is to breathe four or five breaths into a paper bag to increase carbon dioxide levels, allowing better blood flow to your brain. A more permanent solution is to address the way you breathe every day.
The Buteyko Breathing Method
Dr. Buteyko discovered that the level of carbon dioxide in your lungs correlates to your ability to hold your breath after normal exhalation. The Buteyko Method includes a simple self-test for estimating your carbon dioxide levels. You can use a stopwatch or simply count the number of seconds to yourself. Here is the process:
- Sit straight without crossing your legs and breathe comfortably and steadily.
- Take a small, silent breath in and out through your nose. After exhaling, pinch your nose to keep air from entering.
- Start your stopwatch and hold your breath until you feel the first definite desire to breathe.
- When you feel the first urge to breathe, resume breathing and note the time. The urge to breathe may come in the form of involuntary movements of your breathing muscles, or your tummy may jerk or your throat may contract. This is not a breath holding competition — what you're measuring is how long you can comfortably and naturally hold your breath.
- Your inhalation should be calm and controlled, through your nose. If you feel like you must take a big breath, then you held your breath too long.
The time you just measured is called the "control pause" or CP, and it reflects the tolerance of your body to carbon dioxide. Short control pause times correlate with low tolerance to CO2 and chronically depleted CO2 levels. Here are the criteria for evaluating your control pause (CP):
- CP 40 to 60 seconds: Indicates a normal, healthy breathing pattern, and excellent physical endurance
- CP 20 to 40 seconds: Indicates mild breathing impairment, moderate tolerance to physical exercise, and potential for health problems in the future (most folks fall into this category)
- CP 10 to 20 seconds: Indicates significant breathing impairment and poor tolerance to physical exercise; nasal breath training and lifestyle modifications are recommended (potential areas are poor diet, overweight, excess stress, excess alcohol, etc.)
- CP under 10 seconds: Serious breathing impairment, very poor exercise tolerance, and chronic health problems; Dr. Buteyko recommends consulting a Buteyko practitioner for assistance
In summary, the shorter your CP, the more easily you'll get breathless during physical exercise. If your CP is less than 20 seconds, NEVER have your mouth open during exercise, as your breathing is too unstable.
This is particularly important if you have asthma. The good news is that you will feel better and improve your exercise endurance with each five-second increase in your CP, which you can accomplish by incorporating the following Buteyko breathing exercise.
How to Improve Your Control Pause (CP)
The first step to increase your CP is to learn how to unblock your nose with the following breath hold exercise. While this exercise is a perfectly safe exercise for the vast majority of people, if you have any cardiac problems, high blood pressure, are pregnant, have type 1 diabetes, panic attacks, or any serious health concern, then please do not hold your breath beyond the first urges to breathe.
Repeat the following exercise several times in succession, waiting about 30 to 60 seconds in between rounds. And do the exercise on a regular basis.
- Sit up straight
- Take a small breath in through your nose, and a small breath out
- Pinch your nose with your fingers and hold your breath. Keep your mouth closed
- Gently nod your head or sway your body until you feel that you cannot hold your breath any longer (Hold your nose until you feel a strong desire to breathe)
- When you need to breathe in, let go of your nose, and breathe gently through it, in and out, with your mouth closed
- Calm your breathing as soon as possible
Breathing Correctly Is a Simple and Free Way to Boost Your Health and Fitness
The Buteyko Breathing Method is a powerful and inexpensive tool that can help improve your health, longevity, quality of life, and athletic performance. I strongly recommend integrating it into your lifestyle, and when you're ready, into your exercise. Just remember to progress slowly with exercise and gradually decrease the time that you need to rely on mouth breathing.
To learn more, I highly recommend Patrick's excellent book, "The Oxygen Advantage," as well as his DVD set. The book contains both detailed and simplified descriptions of each Buteyko breathing exercise, along with quick reference guides, case studies, and scientific details to help you understand and apply the Oxygen Advantage program to improve your health and fitness.