Causes and Diagnoses

Causes and Diagnoses of Bronchitis

Viral and bacterial infections usually cause acute bronchitis, while smoking and exposure to pollution are related to chronic bronchitis.

People suffering from allergies or exposure to cigarette smoke and chemicals are also more likely to develop acute bronchitis.

Chronic bronchitis can also be linked to other conditions, including:

• Asthma 
• Emphysema
• Pulmonary fibrosis
• Tuberculosis
• Sinusitis
• Upper respiratory infections

Diagnosing bronchitis 

A diagnosis of either acute or chronic bronchitis will begin with a physical exam and discussion of your symptoms. Other tests may include:

• Sputum test: You may be asked to provide a sample of mucus to be checked for bacteria.
• Nasal or throat swab: These tests also check for the presence of bacteria.
• Spirometry: This test measures the quantity and speed of air you exhale to estimate how much your bronchial tubes are inflamed and narrowed.
• Peak flow meter: This device measures how hard you can exhale. Peak flow meters can be used at home to monitor your condition.
• Arterial blood gas: This blood test checks the amount of oxygen and carbon dioxide in your blood and measures your blood’s acidity.
• Pulse oximetry: An oximeter measures the amount of oxygen in your blood with a sensor that’s clipped onto your finger.
• Chest X-ray: This test can identify the presence of pneumonia or other blockages in the airway.
• Computed tomography (CT) scan: This test combines X-ray and computer technology to produce detailed cross-sectional images of your chest cavity.

Symptoms of both acute and chronic bronchitis include excessive mucus, a deep cough, shortness of breath, wheezing and chest discomfort.