Causes and Diagnoses
Causes and Diagnoses of Chronic Cough
When a cough lasts for more than eight weeks, it usually has a medical condition as its underlying cause. The five main causes for a chronic cough are:
- Postnasal drip
- Gastroesophageal reflux disease (GERD)
- Blockage or tumor (abnormal X-ray)
In addition, there are other conditions that are less common causes for chronic cough, including:
- Sjögren syndrome
- Aspiration pneumonia
- Medication for hypertension or heart failure (ace inhibitors)
Diagnosing chronic cough
Diagnosis of your chronic cough 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.
- Methacholine test: If your airways constrict after inhaling methacholine—a common asthma trigger—a diagnosis of asthma can be confirmed.
- X-ray: A chest X-ray can identify the presence of blockages or fluids creating pressure.
- Computed tomography (CT) scan: This test combines X-ray and computer technology to produce detailed cross-sectional images of your chest cavity.
- Bronchoscopy: An endoscope (a thin, flexible tube with a light and camera on the end) is inserted into your airway to check for blockages.