I've had my chest x-ray and the results are clear. I've had a cough for 1 month, why is this happening?
Not all causes of cough are manifested on a chest Xray. For example, asthma and bronchitis, also known as airway disease, may not have any manifestations on a chest Xray. You should discuss your symptoms with your health care provider.
X-rays only show lungs and the cough was probably in the bronchi (the tubes that lead into the lungs). You have my literal sympathy since I get this once a year.