Can doctors usually tell if a person has bacterial bronchitis without an x-ray?

Yes: Bronchitis is not often detectable on a chest x-ray. This test is performed to rule out an associated pneumonia or other underlying lung issues which may have similar presentations bronchitis is a clinical diagnosis based on symptoms, physical findings and lab tests.

Bronchitis - no xray: Bronchitis is easily diagnosed by listening to the chest. One does not need x-ray to diagnose or confirm it. Nowadays, even simple pneumonias do not need x-rays for diagnosis.

Yes...: This diagnosis is made on clinical grounds: your symptoms and physical exam. Blood work can sometimes be helpful. A chest x-ray can be done to determine whether or not you have pneumonia but it does not diagnose acute bronchitis.