Do you sigh a lot? It’s your body telling you to breathe deeper and there are health benefits to it

I don’t know about you but I find myself sighing more and more with every passing birthday. One more candle to muster breath and blow out. Hurrah.
Already, I feel a long exhalation coming on each time I have to stand up, climb the stairs or recall a password. Basically, it’s any task that requires physical exertion and/or mental acrobatics, which is pretty much all day, every day. Sigh.
Then, I came across an article on CNN that sighing is actually good for you and held my breath just a little. People who sigh may be calmer and have a slower heart rate, lower blood pressure and better digestion. 
As it turned out, the medulla oblongata in your brain is the respiratory centre that keeps you breathing automatically. This control tower, located in the lowest part of the brain and brainstem, regulates your respiratory rate and “responds to inputs from sensors in various areas of the body”, said Dr Steve Yang, a respiratory physician and intensivist with Mount Elizabeth Hospital.
“These sensors inform the respiratory centre about changes in the blood carbon dioxide levels, oxygen levels and pH levels,” he explained. The respiratory centre then adjusts your breathing rate accordingly “by sending impulses to the muscles of the respiratory system to adjust the depth and rate of breathing”.
If you aren’t breathing right, your body might make you give out an Eeyore-sized sigh.
I found out that my propensity to sigh could be my body’s way to snap me out of shallow breathing, which can be brought on by stress, anxiety, fear or just plain old bad habit, according to Jaclyn Chow, the principal physiotherapist with Heart & Lung Physio.
“Shallow breathing is essentially hypoventilation and it often happens when someone is mouth-breathing,” said Chow. During hypoventilation, carbon dioxide levels in the blood rise, stimulating the respiratory centre to make you breathe deeper than usual to normalise the carbon dioxide levels, she explained. “This, then, leads to sighing.”
Dr Yang also agreed that rapid, shallow breaths aren’t good news. When carbon dioxide levels increase, your body becomes too alkaline and develops alkalosis, which is the reason why you feel dizzy, lightheaded and even tingling in the hands and feet, he said.
Your normal respiratory rate decreases from birth to adulthood, said Dr Steve Yang, a respiratory physician and intensivist with Mount Elizabeth Hospital:
“Shallow breathing is not sustainable and you will naturally slow your breathing to allow your body to adjust back to the normal pH,” said Dr Yang.
I know my shoulders, rather than my diaphragm, move more when I have a pressing deadline to meet, which indicates that I’m not breathing as deeply as I should be. And it’s not a good thing.
“Shallow breathing creates a situation, where air may not make it to the deeper air sacs at the base of your lungs,” said Chow.
“Shallow breathing is the opposite of diaphragmatic breathing or belly breathing, where the muscles of the neck and chest are being used to inhale instead of the diaphragm, which is our main muscle for breathing,” she said.
“This results in added tension in the neck, shoulder and chest muscles, causing common symptoms like neck and shoulder aches.”
The deep inhalation and longer-than-usual exhalation during a sigh increase the surface area of the lungs, and improve gas exchange to remove excess carbon dioxide more efficiently from the body, said Chow.
“Hence, sighing plays an important role in preventing the collapse of the alveoli (tiny, balloon-shaped air sacs in the lungs), and restores our lung compliance (lungs’ ability to expand). It also helps to restore oxygen and carbon dioxide levels when they become too low or high,” she said.
And as it turns out, you may be sighing more than you think. “The average person involuntarily sighs once every five minutes, making that 12 sighs per hour while we are awake,” said Chow.
Furthermore, sighing activates the parasympathetic nervous system and “can lead to slower heart rate, blood pressure drops and improved digestion”, said Dr Yang.
The parasympathetic nervous system works like your body’s autopilot mode. It controls all the bodily functions you don’t have to consciously tell yourself to perform to stay alive. Like blinking, digesting, producing urine, sweating, making your heart beat a certain rate, and of course, breathing.
Your body apparently prefers to operate in this slow, deep breathing mode. “The brake works more healthfully than the accelerator here,” said Professor David Spiegel, the director of the Center On Stress And Health at Stanford University School of Medicine, in the article, contrasting sighing to the sharp, shallow breathing that preps us to fight or flee.
“You’re immediately soothing yourself in a rather rapid way.”
IS THERE A DIFFERENCE BETWEEN SIGHING AND DEEP BREATHING?
“Sighing is similar to deep breathing,” said Dr Yang, “except that for sighing, the exhalation is longer and utilises the lung’s natural elasticity to effect exhalation.” Sighing is also usually involuntary, added Chow.
Deep breathing, on the other hand, is done “under the control of the cortical areas of the brain, is much faster and involves the active use of the muscles of respiration”, said Dr Yang.
However, Chow is “very cautious when prescribing deep breathing exercises because when done incorrectly, they can result in hyperventilation”. “For most people, deep breathing means inflating the chest wall.
“But the beneficial effects of deep breathing can only be achieved if it’s done properly through diaphragmatic breathing,” she cautioned.
CAN WE GET MORE BENEFITS OUT OF SIGHING?
Prof Spiegel recommended cyclic sighing, which involves breathing in through your nose until you’ve comfortably filled your lungs. Then, take a second, deeper sip of air to expand your lungs as much as possible. Next, very slowly, exhale through your mouth until all the air is gone. Repeat for five minutes daily.
I’m not the type to sign up for yoga classes or sit in a quiet room with my thoughts, so I was pretty relieved when I read that cyclic sighing, compared with other forms of controlled breathing exercises and even meditation, was found to be the most effective at improving mood and reducing respiratory rate in Prof Spiegel’s study published in Cell Reports Medicine last year.
“Controlled breathing exercises may have a more rapid, more direct effect on physiology than mindfulness,” Prof Spiegel said on the Stanford University website.
According to Chow, box breathing, compared with cyclic sighing, is even better at relaxing you. Like sighing, box breathing also focuses on drawing out the exhalation duration to activate the parasympathetic system – but with the addition of breath holding.
Breath holds, said Chow, calm down and regulate the autonomic nervous system, which “causes relaxation and improves mood”.
But if attempting these various breathing techniques knocks the wind out of you, go back to the basics, said Chow, and simply focus on using your diaphragm to breathe “properly and optimally”.
“Take ‘breathing breaks’ throughout the day, which involve slow, deep breaths with longer exhalation instead of rushing to take the next breath,” she suggested. “Focus more on exhaling rather than trying to increase the volume you’re inhaling.”
I breathed a sigh of relief.