How to diagnose Bronchitis ?
Your doctor usually will diagnose bronchitis based on your signs and symptoms. He or she may ask questions about your cough, such as how long you've had it, what you're coughing up, and how much you cough.
                
Your doctor also will likely ask:
                
About your medical history
                
Whether you've recently had a cold or the flu
                
Whether you smoke or spend time around others who smoke
                
Whether you've been exposed to dust, fumes, vapors, or air pollution
                
Your doctor will use a stethoscope to listen for wheezing (a whistling or squeaky sound when you breathe) or other abnormal sounds in your lungs. He or she also may:
                
Look at your mucus to see whether you have a bacterial infection
                
Test the oxygen levels in your blood using a sensor attached to your fingertip or toe
                
Recommend a chest x ray, lung function tests, or blood tests