Breathing Mechanics of through Masks

Breathing through mask is not an easy task as human body is designed to exchange the necessary oxygen and Carbon dioxide against a pressure gradient which became a changed scene  when we breath through mask.

Every inhalation is under stress , prolonged and laboured ,

Everyexhalation is forced to go through mask .

To protect our whole body against this corona virus from entering inside ,our lungs are paying the cost.
Still nobody is talking about lungs... 
We need to train them as we are imposing excessive burden on those.

The pressure in thelungs will increase, and the air that was in thelungs will be forced out towards the lower air pressure outside the body.

During inspiration, the diaphragm and external intercostal muscles contract, causing the rib cage to expand and move outward, and expanding the thoracic cavity and lung volume. This creates a lower pressure within the lungthan that of the atmosphere, causing air to be drawn into the lungs.

Similar to intra-alveolar pressure, intrapleural pressure also changes during the different phases of breathing. However, due to certain characteristics of the lungs, the intrapleural pressure is always lower than, or negative to, the intra-alveolar pressure (and therefore also to atmospheric pressure).

Now , what happens when we breathe through mask 
wearing a mask is reducing the intake of oxygen—or forcing us to breathe in our own carbon dioxide. 
CO2 is present in the atmosphere at a level of about 0.04%. It is dangerous in an atmosphere when it is greater than about 10% like inside a mask 
according to the National Institutes of Health (NIH). They say that inhaling high levels of carbon dioxide (CO2) may be life-threatening. Hypercapnia (carbon dioxide toxicity) can also cause headache, vertigo, double vision, inability to concentrate, tinnitus (hearing a noise, like a ringing or buzzing, that’s not caused by an outside source), seizures, or suffocation due to displacement of air.  
Also if we talk about pressure gradient , that is also affect because of ineffective development of required negative pressure inside the lungs to suck the oxygen in.
There is always a positive pressure gradient present inside which does not allow the complete escape of carbon dioxide from lungs and hence ventilation become difficult at alveolar level .
This is the reason why we feel suffocation and difficult , laboured breathing inside the mask .

Dr. Avinash Saini

Physiotherapist