Masks do not reduce oxygen intake or increase the amount of carbon dioxide you take in when breathing.
Editor’s note: This article was published on July 22, 2020. COVID-19 information and recommendations are subject to change. For the most up-to-date information, visit the Centers for Disease Control and Prevention (CDC) website or view our most recent COVID-19 blog posts.
Most people do not like wearing masks. They can be hot and you may feel that wearing a mask makes it harder to breathe. Despite these discomforts, masks do not reduce oxygen intake or increase the amount of carbon dioxide you take in when breathing. Claims to the contrary are false.
“In most cases, masks will not cause you any harm from reducing your oxygen intake and increasing your carbon dioxide levels,” said Michelle Kaiser, infection preventionist at Marshfield Clinic Health System. “All types of masks are made to allow small particles like oxygen and carbon dioxide to flow through the mask.”
Masks may cause issues if you have severe breathing problems, such as chronic obstructive pulmonary disease (COPD). This is why the Centers for Disease Control and Prevention does not recommend individuals with such health conditions wear masks. People with less severe breathing problems, such as asthma, should be able to tolerate a mask. If you have any concerns about wearing a mask, you should talk with your doctor.
Below are additional myths about wearing masks:
Can wearing a mask cause hypoxia or hypercapnia?
Hypoxia is when your body is not able to get enough oxygen. Hypercapnia is when carbon dioxide levels are elevated in your blood. Both conditions can cause dizziness, shortness of breath, headache and many other symptoms.
Wearing a mask is unlikely to cause these types of conditions, and only individuals with other chronic breathing conditions like COPD could experience these symptoms while wearing a mask.
Does a mask collect CO2?
Carbon dioxide can get trapped inside of the mask where you breathe, but not at high enough levels that could cause hypercapnia.
Carbon dioxide is made up of tiny particles, which can easily pass through the mask or out the sides of the mask.
“Masks are designed to trap large particles from respiratory droplets like those common in COVID-19,” Kaiser said. “The fact that they can trap larger particles while also letting smaller particles go through is why masks are effective ways to flatten the curve.”
Are N95 respirators harder to breathe through?
Compared to a cloth face covering, N95 respirators do make it harder to breathe. However, they do not collect carbon dioxide or restrict oxygen at a high enough level to affect your health.
N95 respirators were created to protect against even smaller particles than average masks and also splashes and sprays common in health care professions. The CDC recommends the general public not wear N95 respirators because there is a shortage of N95 respirators and health care workers on the front lines need them to do their jobs. N95 respirators are most effective and safe when passing a medical screening and being properly fit tested.
“During the COVID-19 pandemic, many health care workers have had to wear facemasks for the entire day when caring for patients. Surgical staff have always worn facemasks during surgeries, which can go for several hours,” Kaiser said. “Most of the complaints about N95 respirators are related to overheating or causing skin irritation not lack of oxygen.”
If you have a chronic health condition that affects the way you breathe, you should talk to your doctor about whether you should wear a mask when social distancing cannot be maintained.
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If masks don't effect oxygen levels then why is it when I laid in a hospital bed my oxygen sensor alarm would not stop going off? There was no effort being put on my system and the sensor kept going off until they removed the mask. I feel your study is more lies and propaganda than facts. I also saw a man use a sensor when he wore a mask and his sensor was altering him he was not getting the proper amount of oxygen. Studies have been done on influenza and on Covid and they say the mask does not work. So in your article you tell everyone they do. Are you lying or pushing propaganda to make everyone believe they are safer complying with prodicals because the experts don't know?
Your article states: “All types of masks are made to allow small particles like oxygen and carbon dioxide to flow through the mask.”. If these particles can get through the mask, how does the mask protect us from the Covid-19 virus particles? Are they larger than the oxygen and carbon dioxide particles? I am not against wearing masks, but my understanding is that the virus particles are quite small, too, so am wondering how it works.
Hello Mary,
We reached out to the infection prevention expert we interviewed for the story to get her thoughts – here is what she had to say:
'Both are very small, Carbon dioxide molecules are tiny, and its true, while the virus itself is miniscule, the way it spreads is by hitch hiking on respiratory droplets, which are much larger than the carbon dioxide molecules.'
Hope that helps answer your question,
Jake
So can the typical masks people are wearing now prevent the virus from leaving your mouth or entering your mouth?
Hello Mary,
We reached out to the infection prevention expert we interviewed for the story to get her thoughts – here is what she had to say:
"In general masks are one piece of the important puzzle to prevent and control the spread of COVID. The CDC recommends the utilization of a cloth face cover.
'Cloth face coverings are recommended as a simple barrier to help prevent respiratory droplets from traveling into the air and onto other people when the person wearing the cloth face covering coughs, sneezes, talks, or raises their voice as a method of “Source control”.' 'this strategy, in combination with prudent hand hygiene and practicing social distancing, help us prevent the spread of COVID.' 'The cloth face cover is meant to protect other people in case you are infected.'
Long story short, yes it protects others in case you are infected, however, this method is best implemented when everyone wears masks and therefore provides more universal protection for those around us and for us to be around others. We are finding that although people may feel well or appear healthy, they may go on to develop symptoms and be positive for COVID and there is potential to be infectious prior to symptom onset. Hence why masking is important."
Hope that helps answer your question,
Jake
“All types of masks are made to allow small particles like oxygen and carbon dioxide to flow through the mask." I have read that the Covid 19 virus particles are also miniscule. If the oxygen and carbon dioxide particles can pass through a mask, how does the mask protect from the virus? Are the virus particles larger?
I am still unable to Pin your articles to Pinterest. For probably a year now, I receive an Oops. Could not save this page error. Any idea why that would be?
Hello Annette,
We are sorry to hear about the problems you are having Pinning our articles on Pintrest. We will look into it to see how we can get it fixed. Thank you again for making us aware.
Great article
The first paragraph contradicts the second one. First it says a mask doesn't reduce oxygen and the second paragraph says it doesn't harm you to have your oxygen reduced. I find my breathing much more labored with a mask as I have COPD and I DO notice a big difference. I couldn't do any physical labor with one on.
Hello,
We note in the article that: 'Masks may cause issues if you have severe breathing problems, such as chronic obstructive pulmonary disease (COPD). This is why the Centers for Disease Control and Prevention does not recommend individuals with such health conditions wear masks. People with less severe breathing problems, such as asthma, should be able to tolerate a mask. If you have any concerns about wearing a mask, you should talk with your doctor.
Thank you and I hope hat helps,
Jake
I DO have COPD but I'm not about to get into an argument with personnel in grocery stores, etc. about NOT wearing a mask. People aren't changing their masks often enough anyway so they probably aren't very effective in the long run. I have N95 masks which are very difficult to walk and breathe through but I'm protected from others whereas the flimsy ones you get at the clinics don't protect you, just other people.
If you would watch the video online where it shows the mucus particles going right through 1, 2 & 3 layers masks its scary. I think we're pretty much doomed and we will all eventually contract it, mask or not.
Is anyone telling people to wear their mask no more than 2 hours? The girl at Marshfield said you can wear them over and over which is NOT true and she should be informed. Over and over for a maximum of 2 hours total which I doubt most people would keep track of.
Have oxygen level tests been done while wearing a mask?
Hello Patti,
We reached out to the infection prevention expert we interviewed for the story to get her thoughts – here is what she had to say:
'There are many videos out there demonstrating healthcare providers wearing various types of masks and various numbers of masks without any impact on oxygenation. According to the American Lung Association, masks absolutely do not cause low oxygen levels.'
Here is a link to the American Lung Association that may be helpful: https://www.lung.org/blog/covid-masks
Hope that helps answer your question,
Jake
I have heard it said that a person already infected with a virus wearing a mask will reinfect themselves by breathing in the expelled virus particles. As ridiculous as that sounds, I cannot believe that. But a medical opinion surrounding the concept might be helpful to some. My opinion… if you have the virus, you have the virus.
Hi Nora, I'm not a doctor or a nurse but if you're already sick then it wouldn't hurt you to breathe your own germs back in through your nose/lungs. If you're already infected you can't get MORE infected. I hope that makes sense.