Hello Milind ,
Welcome to Healthcare Magic forum.
Bilateral Hilar congestion on chest xray is a radiological finding and needs clinical correlation for coming to a diagnosis.
The lungs are situated bilaterally around the central part of chest (mediastinum) which contains the heart and major blood vessels supplying the lungs and body.The area where the lungs are connected to the centre is called hilum of that lung and it contains bronchus
and the blood vessels.
When the lungs are having any pathology like infection, allergy, viral pneumonia
, pulmonary edema
etc the blood vessels in hilum are engorged and cast white prominent shadows on xrays which is called hilar congestion.
It can occur in mild respiratory infections as well as start of pneumonitis
to chronic infections like tuberculosis
but the clinical findings on chest auscultation and detailed examination as well as blood tests like cbc, esr may help your doctor to differentiate between them .
If there are no findings or symptoms in the child and all tests are normal it can be termed as a normal finding too.
Hope I have answered your query.