Bronchitis is a condition where the bronchial tubes, which carry air to and from the lungs, become inflamed. This inflammation causes coughing, with mucus production, wheezing, shortness of breath, and chest discomfort. Bronchitis can be acute or chronic. Acute bronchitis comes on quickly and lasts for a short time, usually less than 10 days. Chronic bronchitis is a long-term condition where symptoms persist for months or years. Understanding the differences between acute and chronic bronchitis can help determine appropriate treatments.
What is Acute Bronchitis?
Acute bronchitis is a short-term inflammation of the bronchial tubes. It often occurs after having a cold or respiratory infection caused by a virus. Acute bronchitis can also sometimes be caused by bacteria. The most common viruses that cause acute bronchitis are influenza A and B, parainfluenza, respiratory syncytial virus (RSV), adenovirus, and coronavirus. Less commonly, acute bronchitis can occur after irritation from inhaled substances like tobacco smoke, dust, fumes, vapors, and air pollution.
With acute viral bronchitis, the immune system sends white blood cells to the bronchi in response to the virus infection. This causes inflammation, swelling, and more mucus production. The swelling narrows the airways, making coughing an instinctual response to try and clear the mucus. Other acute bronchitis symptoms include:
- Coughing up mucus (phlegm), which may be clear, white, yellow or green
- Chest discomfort or tightness
- Mild wheezing or shortness of breath
- Sore throat
- Fatigue
- Headache
- Fever and chills
In otherwise healthy individuals, acute bronchitis usually resolves on its own within a week or two without complications. Severe cases may last up to 10 days. Those with weakened immune systems, heart or lung disease, may experience more severe and prolonged acute bronchitis.
What is Chronic Bronchitis?
Chronic bronchitis is defined as a productive cough that lasts for 3 months or more per year, for at least 2 years in a row. This long-term inflammation causes excessive mucus production, which narrows the bronchi resulting in frequent coughing fits. Chronic bronchitis is one of the conditions classified as chronic obstructive pulmonary disease (COPD) along with emphysema and refractory (non-reversible) asthma.
The most common cause of chronic bronchitis is smoking cigarettes. The inhaled smoke causes constant irritation and damage to the bronchial tubes. However, chronic bronchitis can also occur in those exposed long-term to air pollution, dust, or chemical fumes. Rarely, a genetic condition called primary ciliary dyskinesia causes impaired cilia function which can lead to chronic bronchitis.
Common symptoms of chronic bronchitis include:
- Coughing up sputum most days of the month, for at least 3 months a year, two years in a row
- Shortness of breath especially with exertion
- Wheezing
- Tightness in the chest
- Fatigue
Chronic bronchitis causes gradual destruction of the bronchial tubes and lung tissue over time, resulting in difficulty breathing. The decreased airflow can lead to bacterial lung infections. Exacerbations or flares of chronic bronchitis symptoms occur periodically and are often triggered by lung infections or exposure to air pollution.
Differences between Acute and Chronic Bronchitis
There are several key differences between acute bronchitis and chronic bronchitis:
| Acute Bronchitis | Chronic Bronchitis |
|---|---|
| Short-term (less than 10 days) | Long-term (months or years) |
| Sudden onset of cough | Cough persists for a long time |
| Usually caused by viruses | Usually caused by smoking or environmental irritants |
| Associated with cold or respiratory illness | Occurs independently without other illness |
| No permanent lung damage | Progressive lung damage occurs |
| Rarely recurrent | Repeating episodes are common |
| Rare complications | Prone to complications like infections |
| Full recovery expected | May lead to COPD/emphysema |
While acute bronchitis is usually caused by a virus, about 10% of cases are due to bacteria, most commonly Mycoplasma pneumoniae. Acute viral bronchitis does not respond to antibiotic treatment and resolves on its own, whereas acute bacterial bronchitis may require antibiotics.
Chronic bronchitis causes permanent changes to the lung tissue and airways. The damage from inflammation causes the cilia (tiny hairs) in the trachea and bronchi to stop working properly. This makes it difficult to clear mucus, which plugs the airways and provides an environment for infection. Acute bronchitis does not cause lasting damage as the inflammation is temporary.
Diagnosing Acute vs. Chronic Bronchitis
Acute and chronic bronchitis share some similar symptoms, so identifying which type you have can help guide the proper treatment. Doctors diagnose acute vs chronic bronchitis through:
- Medical history – The doctor will ask about your symptoms, when they started, any underlying conditions, family history of lung disease, and environmental/occupational exposures.
- Physical exam – Listening to your breathing through a stethoscope can reveal wheezing, crackling, or other abnormal sounds.
- Imaging tests – A chest X-ray or CT scan may be done to look for signs of infection or other lung problems.
- Lung function tests – Spirometry is done to measure how well your lungs inhale and exhale air.
- Lab tests – A sputum culture can identify if bacteria is causing infection. A blood test looks for signs of infection.
In acute bronchitis, the doctor will focus on ruling out pneumonia or other complications. Chronic bronchitis involves testing lung function over time to assess irreversible damage.
Key Points in Diagnosis
- Acute bronchitis symptoms resolve in days to weeks
- Chronic bronchitis involves a persistent cough for months or years
- Chest imaging can exclude other lung disease
- Lung function tests assess reversibility of airflow limitation
- Cultures help determine if bacteria are causing infection
Treating Acute vs. Chronic Bronchitis
Treatment options differ significantly for acute bronchitis versus chronic bronchitis. Acute viral bronchitis usually resolves on its own without any specific treatment. Plenty of rest and fluids are recommended. Over-the-counter cough medications may provide symptom relief.
Treatment options for acute bronchitis may include:
- Cough suppressants like dextromethorphan
- Expectorants to loosen mucus like guaifenesin
- Pain relievers like acetaminophen or ibuprofen
- Inhaled bronchodilators like albuterol for wheezing
- Antibiotics if caused by bacterial infection
- Oxygen therapy if oxygen levels are low
For chronic bronchitis, the goals are reducing inflammation and managing symptoms. Quitting smoking and avoiding pollutants and lung irritants is essential. Medications commonly used include:
- Bronchodilators to open airways like albuterol
- Inhaled steroids like budesonide to reduce swelling
- Antibiotics for bacterial lung infections
- Oxygen therapy if oxygen saturation is low
- Pulmonary rehabilitation to improve breathing techniques
Patients with chronic bronchitis should receive an annual flu shot and be vaccinated against pneumococcal pneumonia to prevent infections. For severe chronic bronchitis, surgery may be an option to remove damaged lung tissue. Lung volume reduction surgery or lung transplantation may benefit some patients.
Key Points in Treatment
- Acute bronchitis is usually viral and resolves on its own
- Chronic bronchitis requires lifestyle changes and medications
- Bronchodilators and steroids help manage chronic bronchitis
- Antibiotics only help if there is bacterial infection
- Surgery may benefit severe chronic bronchitis
Preventing Bronchitis
You can take steps to prevent acute bronchitis from recurring and lower your risk of developing chronic bronchitis:
- Get an annual flu shot and COVID-19 vaccine
- Wash hands frequently and sanitize surfaces to avoid spread of viruses
- Avoid cigarette smoke and air pollutants
- Use a humidifier to keep airways moist
- Wear a face mask in cold weather to warm and humidify air
- Take over-the-counter Vitamin C and Zinc which may strengthen immunity
- Avoid irritants like dusts, fumes, and chemicals
The most important way to prevent chronic bronchitis is not smoking or quitting smoking. Secondhand smoke should also be avoided. Implementing health and safety measures at home and work can reduce exposure to environmental toxins. Eating a balanced diet and exercising regularly may also help strengthen lung health.
Key Points for Prevention
- Get recommended vaccines
- Wash hands often and disinfect surfaces
- Don’t smoke and avoid secondhand smoke
- Use a humidifier and face mask in winter
- Reduce exposure to fumes, chemicals, dusts
- Eat healthy foods and exercise regularly
Conclusion
Acute bronchitis is temporary swelling of the bronchial tubes, often after a viral illness. It resolves quickly without permanent lung damage. Chronic bronchitis involves persistent long-term inflammation, usually from smoking, air pollution, or lung irritants. It can lead to serious lung impairment.
Key differences include duration, causes, recurrence, and extent of lung damage between acute and chronic bronchitis. While acute bronchitis is typically viral and self-resolves, chronic bronchitis requires active treatment and lifestyle changes to manage symptoms and slow progression.
Preventing bronchitis involves getting immunized against respiratory infections, avoiding irritants, not smoking, and maintaining overall health. Understanding the differences between acute viral bronchitis and chronic bronchitis allows prompt diagnosis and initiation of appropriate therapy.