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Long-Term Respiratory Effects of COVID-19

Published on Nov 05, 2021   -  5 min read


Since its outbreak, COVID-19 has been a mystery for healthcare professionals and the general public while considering the variants and long-term effects it has developed. Scroll down this article to get an insight into the long-term respiratory effects of COVID-19.

Long-Term Respiratory Effects of COVID-19

Post-COVID Syndrome:

Although recovery from COVID-19 occurs in a span of a few weeks, the aftermath effects continue even after the period of initial recovery. This phenomenon is called long COVID or post-COVID syndrome. These long haulers of COVID exhibit post-COVID conditions that are present even after four weeks of COVID-19 diagnosis. COVID-19 symptoms can be persistent in older adults and individuals with other comorbidities. However, it can be present in young and healthy people also.

The following are the persistent symptoms of COVID-19:

How Are Lungs Affected by the Coronavirus?

Coronavirus predominantly affects the respiratory system and causes a series of reversible and irreversible damages to the lungs. This, in turn, leads to several complications like pneumonia, acute respiratory distress syndrome (ARDS), and sepsis. The extent of these complications depends on several factors like age, comorbidities present, and the severity of COVID-19 infection.

It is important to note that persons with underlying lung disease are more prone to worsened complications than others. Also, pre-existing conditions like asthma, interstitial lung disease, and chronic obstructive pulmonary disease may exacerbate COVID-19. Pulmonary interstitial fibrosis occurring after initial COVID recovery has brought about immense effects on the quality of life and has resulted in moderate loss of lung function.

How Does Coronavirus Affect the Lung Structure?

1. Diffuse Alveolar Damage:

The virus attaches to the angiotensin-converting enzyme-2 (ACE2) receptor cells and destroys them, through which it attacks the type 2 pneumocytes. The functional impairment of type 2 pneumocytes is dependent on the viral replication and pro-inflammatory cytokine release. As a result, diffuse alveolar damage is caused, characterized by functional impairment of the cells, apoptosis or necrosis, exudate formation, pneumocyte cell desquamation, and hyaline membrane formation.

2. Thrombosis of Alveolar Microcirculation:

The SARS-CoV-2 virus affects the gas exchange in the alveolus by affecting the integrity of the alveolar epithelium or alveolar microcirculation function. The virus targets the vascular endothelial cells and activates them through the ACE-2 receptors, followed by a series of changes that result in thrombosis of alveolar microcirculation.

3. Airway Inflammation:

The pro-inflammatory cytokines released during a COVID-19 infection cause inflammatory infiltration of the trachea, bronchi, and bronchioles, resulting in airway inflammation. This, in turn, reduces the ventilatory function.

What Long-Term Lung Complications Does the SARS-CoV-2 Virus Cause?

COVID pneumonia is characterized by difficulty in breathing due to inflammation and fluid build-up in the lungs. Pneumonia can occur in both the lungs. Fever, shortness of breath, and productive cough are the symptoms associated with COVID pneumonia. In some people, there can be severe breathing difficulties that may result in the need for supplemental oxygen therapy or the use of ventilators. Difficulty in breathing is because the air sacs in the lungs are filled with fluid, thereby reducing the lungs’ ability to take in oxygen. Although pneumonia, in general, is reversible and does not cause long-term effects in the lung, COVID pneumonia causes lung injury that usually takes a few months to recover.

Severe inflammation of the lungs results in acute respiratory distress syndrome. It is a form of lung failure due to fluid leakage from the blood vessels that fill the air sacs. As it is a severe form of respiratory failure, patients affected with ARDS cannot breathe independently and depend on mechanical devices like ventilators or extracorporeal membrane oxygenation (ECMO). ECMO is a lung bypass device that helps in the oxygenation of blood. Unlike pneumonia, ARDS produces lasting effects on the lung, like lung fibrosis or lung scarring. However, ARDS has fatal complications in many cases.

It is a syndrome of abnormal inflammation that occurs due to the spread of infection in the bloodstream, leading to tissue damage and organ failure. The vital organs do not work in a coordinated fashion leading to a massive impact on the long-term functionality of the patient.

During infection with COVID-19, the body’s immune system is trying to fight against the virus. While the immune system is working against coronavirus, another bacteria or virus may invade the body and cause a superinfection, worsening lung damage.

What Factors Increase the Risk of Lung Damage in COVID-19?

1. Severity of the Disease:

The extent of lung damage caused by coronavirus depends on the severity of the COVID-19 infection. There are no lasting scars in the lungs in mild cases, while lung damage is predominant in severe cases.

2. Comorbidities:

Pre-existing health conditions like chronic obstructive pulmonary disease and cardiac diseases increase the severity of the infection and might result in lung damage. Also, older adults are more prone to severe infections due to weakened immunity and elastic lung tissues.

3. Treatment:

Recovery from the infection and lung damage is dependent on factors like type and prompt time of treatment. Well-timed and appropriate treatment helps reduce the extent of lung damage.

Is Lung Damage Reversible After COVID-19?

Recovery of lung damage after COVID-19 is not possible overnight and it takes around three months to a year or more to return to normal as before the COVID-19 infection. Like healing after a bone fracture, lung damage following COVID also takes time and can produce symptoms. It is not possible to run soon after removing a cast following a leg fracture. In the same manner, recovery after COVID also takes time for healing. Patients should continue with the treatment and therapy recommended by the healthcare professional as long as they are advised.

How Can We Reduce the Extent of Lung Damage in COVID-19?

Does Smoking Increase the Extent of Lung Damage?

Nicotine in cigarettes and e-cigarettes is known to cause lung damage, thereby increasing the risk of contracting COVID-19 or respiratory complications associated with COVID. Also, sharing devices and repetitive touching of one’s face and mouth increases the risk of getting an infection.


The damage caused by COVID-19 in the lungs can be controlled to an extent by following appropriate treatment methods and seeking prompt treatment. Also, keep track of your existing medical conditions. Do not treat yourselves even when you are asymptomatic or exhibit only mild symptoms to avoid post-COVID complications.


Last reviewed at:
05 Nov 2021  -  5 min read




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