What is a pulmonary focal infiltrate?

Infiltrate : A pulmonary infiltrate is usually used to describe a chest x-ray. A focal infiltrate means that it is localized to only one area of the lungs, as opposed to diffuse infiltrates which occurs throughout one or both lungs. This description most commonly is used to describe a pneumonia or area of inflammation within the lung.

A finding on an X-ray: it is a finding on an X-ray. It is increase markings or whiteness seen on a radiograph. It is most typically associated with pneumonia. Other causes can be, not taking a deep breath (called atalectasis) , fluid, cancer, or, an autoimmune process, to name a few.