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Is there a specific process through which COVID-19 enters the body? Does COVID-19 first enter through the throat before it "destroys" the lungs?

This article was published on
April 21, 2021

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COVID-19 enters the body through the nose, mouth, and eyes. This happens primarily when someone infected with the virus releases small droplets of liquid that contain part of the virus through actions like coughing, sneezing, speaking, or singing. These small bits of virus range in size, from the wet, teardrop-sized types of droplets you might see when you sneeze, to microscopic ones that are so light and dry, they might remain in the air for hours. When a person is in close contact with these droplets, the virus enters the body through these three areas. Then, the virus lands at the back of the throat, also called the top of the upper respiratory tract, in roughly 80% of people who have mild cases of infection. For other more severe cases, the virus can then move down to the lungs, potentially causing pneumonia, which happens in 15-20% of cases, although most recover. When COVID-19 spreads to the lungs, it does not mean that they will be "destroyed." It means that there is an infection involving fluid within tiny branches of air tubes or sacs in the lungs called 'alveoli.' These air sacs may fill up with so much liquid or pus that they become swollen, and their walls can thicken, so it is hard for oxygen to be processed and delivered through the lungs, making it harder to breathe. Every virus has a different way of infecting humans, though many viruses gain entry into the body through the nose, mouth, and eyes and often cause upper respiratory infections like COVID-19.

COVID-19 enters the body through the nose, mouth, and eyes. This happens primarily when someone infected with the virus releases small droplets of liquid that contain part of the virus through actions like coughing, sneezing, speaking, or singing. These small bits of virus range in size, from the wet, teardrop-sized types of droplets you might see when you sneeze, to microscopic ones that are so light and dry, they might remain in the air for hours. When a person is in close contact with these droplets, the virus enters the body through these three areas. Then, the virus lands at the back of the throat, also called the top of the upper respiratory tract, in roughly 80% of people who have mild cases of infection. For other more severe cases, the virus can then move down to the lungs, potentially causing pneumonia, which happens in 15-20% of cases, although most recover. When COVID-19 spreads to the lungs, it does not mean that they will be "destroyed." It means that there is an infection involving fluid within tiny branches of air tubes or sacs in the lungs called 'alveoli.' These air sacs may fill up with so much liquid or pus that they become swollen, and their walls can thicken, so it is hard for oxygen to be processed and delivered through the lungs, making it harder to breathe. Every virus has a different way of infecting humans, though many viruses gain entry into the body through the nose, mouth, and eyes and often cause upper respiratory infections like COVID-19.

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What our experts say

COVID-19 enters the body through the nose, mouth, and eyes. This happens primarily when someone infected with the virus releases small droplets of liquid that contain part of the virus through actions like coughing, sneezing, speaking, or singing. These small bits of virus range in size, from the wet, teardrop-sized types of droplets you might see when you sneeze, to microscopic ones that are so light and dry, they might remain in the air for hours. When a person is in close contact with these droplets, the virus enters the body through these three areas. Then, the virus lands at the back of the throat, also called the top of the upper respiratory tract, in roughly 80% of people who have mild cases of infection. For other more severe cases, the virus can then move down to the lungs, potentially causing pneumonia, which happens in 15-20% of cases, although most recover.

When COVID-19 spreads to the lungs, it does not mean that they will be "destroyed." It means that there is an infection involving fluid within tiny branches of air tubes or sacs in the lungs called 'alveoli.' These air sacs may fill up with so much liquid or pus that they become swollen, and their walls can thicken, so it is hard for oxygen to be processed and delivered through the lungs, making it harder to breathe.

Every virus has a different way of infecting humans, though many viruses gain entry into the body through the nose, mouth, and eyes and often cause upper respiratory infections like COVID-19.

Context and background

As we learn more about COVID-19 and the way it is spread to humans, we will learn more about why the virus seems to impact the lungs of many people. Unlike most viruses humans come into contact with, COVID-19 is new, so humans have not had the ability to gradually build up their immune systems to defend themselves from the virus over time. This may be part of the reason why the virus continues to spread rapidly around the world and can cause significant symptoms in 20% of cases.

Resources

  1. Q&A: How is COVID-19 transmitted? (WHO)
  2. Alveoli (NCI)
  3. Coronaviruses: An Overview of Their Replication and Pathogenesis (NPHEC)
  4. How COVID-19 spreads, 2020 (U.S. CDC)

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