Anita Carmen Choy, MD

Welcome to the new online home of Allergist Anita Carmen Choy, MD. Currently serving adults and children suffering from allergies and asthma, Dr. Choy is a Board Certified Allergist, providing comprehensive medical care for adult and children in the Silicon Valley since 1995.

What Exactly IS Mouth Breathing?

 Respiration, that is, breathing, is not only a vital process for every human, but it’s also an involuntary one that commences the moment we are born, and while we  breathe as long as we live, we don’t always breathe in the best way possible to maintain  optimal health.

Breathing  is meant to happen through the nose, but many people actually breathe through their mouths most or much of the time. While we all breathe through our mouths some of the time, it’s important that we use our nose for the majority of our breathing. Otherwise we can develop some surprising  health issues,  including trouble sleeping, snoring, difficulty concentrating, dental problems and more.

Learning about your own breathing habits, and correcting those that are not the best, can make a huge difference to the quality of your life and to your long term health. 

There are a number of factors that can cause an individual to breathe through the mouth for an extended period of time. Often, the person who starts breathing through the mouth due to one of these factors, forms the habit and once the issue that caused the mouth breathing to start is eliminated, the habit stays, and mouth breathing becomes the normal state.

It’s important to be aware if you tend to breathe through the mouth when you don’t need to, so that you can begin to eliminate the habit and reduce your risk of developing the issues that can come with habitual breaathing through the mouth.

Some of the causes of mouth breathing can include:

  • Nasal Congestion: Often, mouth breathing is the result of nasal congestion that forces a person to breath through the mouth instead of the nose. This can be caused by colds and stuffy noses, allergies, sinus infections and any other type of respiratory condition that affects your ability to breath. Once the congestion clears up, the sufferer often continues to breathe through the mouth, opening the door to new issues.
  • Enlarged Tonsils or Adenoids: When the tonsils and/or adenoids are enlarged or inflamed, you are more likely to develop colds, hoarseness and sore throat. Inflammation of the area can cause an obstruction to comfortable nasal breathing,  increasing the risk of chronic mouth breathing.
  • Thumb Sucking in Children: A child who has sucked his or her thumb in the past have may oral and facial muscles that developed around that habit. This means that the lips may not form a natural seal due to the habit, and the tongue thrust pattern that forms when finger-sucking remains. In severe cases of mouth breathing in children, the actual facial construction can develop incorrectly, causing a receding jawline and other structural and/or musculature issues.
  • A Deviated Nasal Septum: A deviated septum is a common cause of nasal obstruction. It can block one nasal passage and reduce your airway, forcing you to breath through your mouth instead. This can become especially pronounced at night and often leads to unconscious mouth breathing.
  • Tongue Tie: An actual medical condition, the tongue-tie doesn’t allow for the mouth to close properly, thereby impairing nasal breathing. Because a tongue tie reduces upper airway support, it can casue breathing issues if left untreated.


Habitual breathing through the mouth can lead to a broad range of symptoms and risk factors in children and adults. while it can be difficult to know if you are yourself  breathing correctly while sleeping, waking with a dry mouth or very bad breath can be simple and immediate warning signs.

Unchecked, chronic mouth breathing is linked to sleep apnea, dental problems, cognitive decline and chronic fatigue, as well as the deterioration of the body’s production of nitric oxide, a molecule that is vital to the regulation of blood flow, platelet function, immunity, and neurotransmission.

Some common effects of chronic mouth breathing can also help you identify the possibility that you are mouth breathing without realizing it:

  • Dry mouth when waking
  • Bad breath
  • Nasal obstruction or congestion
  • Snoring
  • Sleep disorders, including sleep apnea
  • Poor concentration and academic performance
  • Ear and throat infections

Additional symptoms that typically result from chronic childhood mouth breathing:

  • Misaligned teeth and overbite
  • A history of dental issues, including cavities and gingivitis
  • Speech impediments, especially lisps
  • Chewing abnormalities
  • Facial deformities, including flatter facial features, and receding chin

When we breath in air through the nose, the air we breath is filtered as it makes its way through the nasal passage and into the mucus-lined windpipe. Both the tiny hairs in the nose and the mucus in the windpipe work to protect our bodies from foreign particles before they are able to enter the lungs.

Once the filtered air enters the lungs, the oxygen is pumped into our bloodstream and circulated throughout the body. And finally, when air exits the body through exhalation, it brings with it carbon dioxide from our cells and other waste materials.

The main advantages of nose breathing include:

  • The Nose Is a  Filter: The nose is lined with cilia — tiny hairs that filter the air we breath before it enters the lungs. Tiny particles that would be able to enter the body through the mouth are stopped by these tiny hairs in the nose during nasal breathing.
  • Nasal Breathing Regulates Air Temperature: The tiny hairs that line the nasal passage help to regulate the temperature of the air we breath before it enters the lungs. It works to cool or warm the air, depending on its temperature. Breathing through the nose ensures that inspired air is at the right temperature for the lungs, promoting proper lung function.
  • It Prevents Dryness: When you breath in through your nose, the air is moistened before it reaches the lungs. By warming and humidifying the air we breath, nose blowing is beneficial to your respiratory system and may help to reduce the risk of common respiratory conditions, like the common cold.
  • Helps to Calm the Mind:  Correct nasal breathing is a huge element of a yoga practice specifically because of its calming effect on the mind.  Breathing exercises in yoga are meant to help you focus on the present and leave you with a relaxed state of mind. When we breath deeply in and out of the nose, it stimulates parasympathetic nerve receptors that are associated with calmness and distributes greater amounts of oxygen throughout the body.
  • Nasal Breathing Boosts Nitric Oxide Production: Nose breathing allows for the production of nitric oxide in our sinuses. Nitric oxide works to relax the inner muscles of our blood vessels, allowing them to widen and increase circulation.

How Is Mouth Breathing Diagnosed?

In children, mouth breathing can be recognized simply enough, so long as the parent keeps an eye out for open-mouthed breathing during the child’s sleep. Unfortunately, it’s often the case the parents become so used to seeing their little ones sleeping that it is quite easy to overlook the fact that the sleeping child is actually not breathing with a closed mouth.

In older children, as the facial structure adapts to the chronically open mouth, the face can become slightly flatter, the chin tilts down and recedes, and the top teeth tend to move forward into an overbite. If you notice any of these characteristics, a dentist or orthodontist can check these symptoms for you.

In adults, most chronic mouth breathing is easy to spot as sufferers tend to eat and breathe more loudly than nose breathers, and often suffer from chronic fatigue, interrupted sleep, respiratory issues and more. If you tend to wake up short of breath or gasping for air, you may be at risk or siffering from sleep apnea, a risk factor for mouth breathers.

If you have any questions or suspect that you or your child might be a chronic mouth breather, a physician specializing in Rhinology should be your first stop in your journey to alleviate the problem.

Can Chronic Mouth Breathing Be Reversed?

Can chronic mouth breathing be reversed?

The cause of the chronic mouth breathing needs to be elucidated and treated. The causes vary from  structural problems to diseases such as nasal allergies, chronic sinusitis, short frenulum or jaw malformation.


The correction may include the multidisciplinary team that includes the allergist, the ENT/ plastic and the orthodontist. Long standing mouth breathing may continue despite correction of the underlying problem due to weak orofacial muscles weakness. A Myofunctional therapist will be very helpful for the rehabilitation and strengthening of both the tongue and facial muscles.

Consult your physician for more information in your specific case.