By Ernst Lamothe Jr
As cold weather remains in effect and people continue retreating indoors, respiratory illnesses such as bronchitis and pneumonia persist. While these seasonal trends are familiar, many Americans remain unsure how to distinguish between common viral infections and more serious lung conditions — or how to avoid them altogether.
“Effective strategies combine clear public-health messaging and community access seasonal vaccination campaigns timed before peak season,” said physician Pranita Ghimire, a pulmonologist at St. Joseph’s Health. “Public education about when to seek care, appropriate antibiotic use and basic prevention is essential.”
1. Virus and lung illness
Ghimire explains that winter’s close indoor contact creates ideal conditions for respiratory viruses to spread.
“Acute bronchitis is most often viral and commonly follows upper-respiratory infections, while pneumonia can be viral or bacterial during winter viral triggers,” said Ghimire. “Seasonal peaks in influenza and RSV in colder months drive increased cases of both bronchitis and pneumonia.”
Bronchitis inflames the bronchial tubes, while pneumonia affects deeper lung tissue and air sacs. Both conditions become more common as households and workplaces seal up against the cold.
2. Symptoms differ
While many respiratory illnesses share features like coughing and fatigue, there are key differences. A cold typically causes runny nose, sneezing and sore throat and rarely involves fever. The flu, however, comes on suddenly with high fevers, intense fatigue, body aches and a heavy cough. Bronchitis is often marked by a persistent, mucus-producing cough that may last weeks, along with chest discomfort and wheezing. Pneumonia presents more alarmingly.
“Pneumonia produces more marked lower-respiratory signs — persistent productive cough, pleuritic chest pain, shortness of breath, higher fevers and often abnormal lung exam or imaging,” said Ghimire. “Symptoms tend to be more severe and prolonged than bronchitis. Distinguishing requires clinical exam and sometimes chest X-ray or tests for pathogens. Influenza usually presents abruptly with high fever, chills, myalgias, headache, prominent fatigue and respiratory symptoms; severity and systemic features are generally greater than a cold.”
3. Who’s most at risk?
Several groups are more vulnerable during the winter respiratory season.
Key risk factors are age, patients who are very young and older adults, chronic lung disease smoking, immunosuppression and chronic cardiovascular,” she said. “I also tell patients crowding and indoor exposure during winter with poor ventilation also raise transmission risk for viral causes. Smoking and preexisting lung disease are repeatedly associated with higher incidence and worse outcomes.”
Other protective steps include regular handwashing, avoiding touching your face, maintaining good indoor ventilation, avoiding tobacco and secondhand smoke, prioritizing sleep, balanced nutrition and exercise and limiting close contact with sick individuals.
4. Treating bronchitis and pneumonia
Treatment depends on the cause. Vaccination is with an annual influenza vaccine and age or risk-appropriate pneumococcal vaccines reduce severe disease and secondary pneumonia. COVID-19 vaccination per guidance also reduces risk of severe lower-respiratory infection.
“It’s essential to reduce exposure, which is to avoid close contact with sick people, improve indoor ventilation and air cleaning in crowded spaces,” said Ghimire. “You have to address modifiable risks such as stop smoking, control chronic conditions and maintain good nutrition and sleep to support immunity.”
These interventions are supported by public-health agencies and infectious-disease guidelines as the most effective population measures.
5. Immune system
Cold weather itself doesn’t create infections, but several biologic and behavioral mechanisms raise susceptibility. Inhaling colder air can reduce antiviral defenses in the nasal and airway epithelium. Behavioral changes in winter — more indoor crowding and reduced ventilation — increase transmission. Together these factors explain why respiratory infections and subsequent lower-respiratory complications rise in winter. There are times when conditions continue to worsen and experts have suggestions to make sure additional problems don’t arise.
“Clinicians typically advise rest and gradual return to activity, maintain hydration and nutrition and continue prescribed medications,” she said. “We also tell patients to use bronchodilators or inhaled medications if indicated; monitor symptoms closely and seek care for worsening problems such as increasing breathlessness, high fever, chest pain, confusion. For pneumonia, arrange follow-ups, often a clinic visit and sometimes repeat chest X-ray in 6–12 weeks to ensure radiographic and functional recovery.”