In this article:
How does COVID-19 affect the respiratory system?
COVID-19 spreads from person to person through respiratory droplets containing the virus. These droplets are released in the environment when an infected person sneezes, coughs, or talks.
These airborne droplets either get inhaled by anyone in the vicinity or land on the surrounding surfaces. If anyone touches the contaminated surface and then touches the eye, nose, or mouth with the same hands, the virus will find a way into the body.
The virus typically enters healthy cells by attaching to the ACE-2 receptor and eventually damages the cells and may even kill them. These receptors are more common in the respiratory system, especially in the lungs.
If the virus stays in the upper respiratory system, it typically causes mild symptoms such as dry cough and sneezing. But if the virus advances further into the lungs, it can cause more severe symptoms such as shortness of breath and low oxygen levels.
What happens to the lungs once infected with COVID-19?
Once the virus infects the lungs, pneumonia occurs. The infection triggers excessive mucus secretion in the airways as a natural defensive response of the body against the virus.
As a result, tiny air pockets in the lungs (air sacs) can get filled with mucus, preventing normal exchange of oxygen and carbon dioxide between blood and air.
In severe cases, the patient may experience extreme breathing difficulties that necessitate supplemental oxygen support and, at times, ventilator support.
Does having a pre-existing lung disease make one susceptible to COVID-19?
Yes and no. There is limited data available for people with asymptomatic infection. Healthy people still can get infected but have a lower chance of having symptoms and especially severe symptoms.
According to a recently published study from China, people with previous lung problems are more likely to have a severe bout of illness from COVID-19, characterized by extreme respiratory distress, which may warrant breathing assistance. (1)
Who is at a high risk of severe COVID-19 from a respiratory standpoint?
What extra precautions should people with preexisting lung problems take against COVID-19?
Currently, COVID-19 is widespread throughout the world. People suffering from chronic lung diseases are at higher risk of falling seriously ill from this infection. Since they are more vulnerable, they have to make extra efforts to keep themselves safe.
For starters, limit your activity outside the house as much as possible and wear a mask if you are forced to step out or when social distancing is not feasible outside the house.
Face touching is to be completely avoided, especially the mouth, eyes, and nose, since these are the entry points for the virus. Touching the face with contaminated hands transfers the virus to the respiratory mucosa, allowing it free passage into the respiratory tract.
Another cardinal rule for staying infection-free is following stringent hand hygiene. Frequently wash your hands with soap and water for at least 20 seconds, especially after touching any surface outside the house.
You can use an alcohol-based hand sanitizer to clean your hands when you are on the move or if water and soap are not readily available. Regularly clean and disinfect all the frequently used/touched surfaces in your home.
Can smoking increase the chances of catching COVID-19?
Yes. Smoking increases the chances of developing the infection via two mechanisms.
First, smoking increases the number of ACE-2 receptors in the lungs where the COVID-19 virus attaches. (4)
Secondly, smoking can cause chronic lung disease, including COPD, and hence can increase the chance of having a severe infection.
In one study that examined about 2,000 patients, the researchers found that smokers were twice as likely and people with COPD were four times more likely to have severe infections compared with healthy non-smokers. (5)
Do all the patients with COVID-19 require ventilator support?
No. A recent study done in NYC showed that about 12% of people who were admitted to the hospital for COVID-19 required intubation and ventilator support. (2)
The actual rate will be lower if you include mildly symptomatic patients who do not get admitted to the hospital and asymptomatic patients.
What is the major difference between COVID-19 and pneumonia?
COVID-19 is a virus that can cause, among other things, pneumonia. Pneumonia is an infection of the lungs that can be caused by various strains of pathogens, such as virus, bacteria, and fungus.
COVID-19, however, is strictly a viral infection.
Does COVID-19 affect only the upper respiratory tract?
No. COVID-19 can affect both, the upper and lower respiratory tract.
What is the difference between the symptoms of SARS and COVID-19 symptoms?
Both SARS and COVID-19 are viral infections that can cause cough, fever, and lower respiratory symptoms. The major distinguishing feature between the two is that SARS is relatively more severe than COVID-19, whereas COVID-19 is more contagious or fast-spreading than SARS.
SARS caused more serious illness, with 20%-30% of those infected requiring a ventilator. (6) Meanwhile, COVID-19 appears to spread more easily than SARS, likely due to a large number of mild to asymptomatic COVID-19 positive patients who remain undiagnosed.
What precautionary measures should be taken against COVID-19?
Social distancing is the biggest enemy of COVID-19. Preventive measures, such as the use of face coverings when possible, frequent handwashing, and frequent cleaning of high-touch surfaces, are important to contain the spread of COVID-19.
Symptoms of COVID-19 range from no symptoms at all to mild and severe. Mild symptoms include dry cough and fever, and severe symptoms include pneumonia and breathing problems that require hospitalization and ICU.
People who are older and with an underlying medical condition are more prone to getting severe COVID-19.
Contact your local healthcare provider immediately if:
- You develop any symptoms suggestive of COVID-19.
- You have been exposed to someone with an infection.
- You have any concerns or doubts regarding the infection.