Respiratory Syncytial Virus (RSV) is a common viral infection that primarily affects the lungs and breathing passages. It is highly contagious, causing cold-like symptoms in most people. Nearly all children experience an RSV infection by age two, and reinfection can occur throughout life. While often mild, RSV can lead to more serious conditions, particularly in certain individuals. RSV can cause shortness of breath, a concern especially for infants, young children, and older adults, who are more susceptible to severe illness. Understanding how RSV impacts the respiratory system is important for recognizing and addressing potential breathing difficulties.
How RSV Affects the Airways
RSV begins its infection in the upper respiratory tract, affecting the nose and throat. It can rapidly spread downwards into the lower respiratory tract, targeting the small airways within the lungs known as bronchioles. This progression can occur quickly, sometimes within days of initial symptoms.
Once in the bronchioles, the virus infects and damages the epithelial cells lining these tiny passages. This triggers a significant inflammatory response, causing the walls of these small air tubes to swell and become inflamed.
This inflammation and cellular damage increase mucus production. Excess mucus, along with dead epithelial cells and other inflammatory debris, can accumulate inside the already narrowed bronchioles. These plugs effectively block or significantly reduce airflow through these breathing passages.
The combination of swollen airway walls and obstructed passages makes it harder for air to enter and exit the lungs. This reduced airflow directly leads to breathing difficulties, including wheezing and shortness of breath. Infants and young children are particularly susceptible to severe symptoms due to their naturally smaller airway diameter, which makes them more easily obstructed.
Recognizing Breathing Difficulties and Other Symptoms
RSV often begins with symptoms similar to a common cold, such as a runny or congested nose, coughing, sneezing, and sometimes a low-grade fever. Individuals may also experience a sore throat or headache. While these initial signs might seem mild, they can progress, indicating a more significant infection, especially with breathing changes.
Monitoring for specific signs of breathing difficulty is important. These include rapid breathing (tachypnea) and wheezing, a high-pitched whistling sound typically heard during exhalation.
Visual cues can also indicate labored breathing. Nasal flaring (nostrils widening with each breath) and chest retractions (skin pulling in around the ribs or collarbone) signify increased effort to breathe. Grunting sounds during breathing and a bluish or grayish tint to the skin, lips, or nail beds (cyanosis) are serious indicators of insufficient oxygen.
Symptoms can vary based on age. Infants, for instance, might not exhibit typical cold symptoms but may instead show irritability, unusual tiredness, or poor feeding, along with breathing difficulties. Very young infants might even experience apnea (brief pauses in breathing). Healthy adults and older children typically experience milder, cold-like symptoms, though severe cases can occur across all age groups.
When to Seek Medical Care
While most RSV infections result in mild, cold-like symptoms that resolve within one to two weeks, it is important to know when to seek medical attention. Immediate care is crucial for signs of significant breathing difficulty, such as severe shortness of breath, marked chest retractions, or grunting sounds. A bluish or grayish discoloration of the skin, lips, or nail beds (cyanosis) signals a lack of oxygen and requires urgent attention.
Other concerning symptoms include pauses in breathing, particularly in young infants. Signs of dehydration, like fewer wet diapers or a very dry mouth, also necessitate evaluation. A notable decrease in alertness, unusual tiredness, or difficulty waking up, along with a high fever in infants under three months, indicate a serious turn in the illness.
Certain individuals face a higher risk of severe RSV illness and should be monitored more closely. These groups include infants (especially those under six months or born prematurely), young children with existing heart or lung conditions, older adults (particularly those over 65 with underlying health issues), and anyone with a weakened immune system.