Usually, doctors do not consider the possibility of bronchitis until a patient has had a persistent cough for five days or more. Once a patient has reached this stage, the doctor must determine if the bronchitis is chronic or acute. Acute bronchitis usually lasts for one to three weeks and is associated with a productive cough. Chronic bronchitis usually is associated with a cough that lasts for more than three months. Chronic bronchitis is often seen in patients with COPD.
It is important for the doctor to distinguish between acute bronchitis and pneumonia. While bronchitis is usually caused by a viral infection, pneumonia is usually caused by bacterial infection, and usually requires treatment with antibiotics. One way to tell the difference is that patients with pneumonia often have a high fever, while patients with bronchitis usually do not.
Usually, a doctor will diagnose bronchitis by doing a physical exam. Most often, there is no need for any further tests. The physical exam includes:
- Listening to the chest when the patient is breathing to detect wheezing and shortness of breath
- Examining the consistency and color of any mucus that is present
- Measuring the patient’s temperature to detect fever
- Speaking with the patient to determine how long they have had the cough and how it has progressed
After the physical exam, the doctor might perform more tests if they believe the patient might have pneumonia or another illness, rather than bronchitis.