Infections

How do viruses get into the lungs?

Various respiratory viruses enter the lungs more frequently during the flu season.

(Bild: magicmine - stock.adobe.com)

Microscopically small pathogens are able to infect the human body and sometimes cause dangerous diseases. Here you can find out how viruses get deep into the lungs.

The lungs, a vital organ for breathing, are particularly susceptible to viruses. Most pathogens enter the body via the upper respiratory tract such as the nose and throat. From there, they can penetrate deep into the lungs and lead to serious illnesses such as pneumonia, bronchitis or even acute respiratory distress syndrome. The most common pathogens are respiratory viruses such as influenza, corona rhino and respiratory syncytial viruses (RSV).

Viruses are inhaled through the nose
The infection begins with the inhalation of virus-laden droplets that are released into the air when infected people cough, sneeze or speak. These droplets enter the body via the nasal mucous membranes or the mouth. Once in the upper respiratory tract, the viruses adhere to the mucous membranes of the nose, throat or larynx and begin to infect cells.

Serious illnesses are imminent
This leads to an inflammatory reaction that irritates the mucous membranes and activates the body's own defenses. They then "migrate" via the windpipe into the bronchi and alveoli. Entry into these deeper areas of the lungs is decisive for the severity of the disease. Here, the viruses can cause more intense inflammation and disruption of gas exchange, leading to breathing difficulties and, in the worst case, pneumonia.

Particularly vulnerable groups of people:

• People with weakened immune systems, for example due to chronic illnesses or immunosuppressive drugs that suppress the normal function of the immune system, are more susceptible to viral infections of the lungs.

• Older people and young children often have a weaker immune system and are therefore at a higher risk of serious respiratory diseases.

• Smokers: Smoking damages the airways and weakens the lungs' defense mechanisms, making it easier for viruses to enter.