Thanks for your question on Health Care Magic. I can understand your concern. Normally on chest x ray bronchus is normal seen because it contains air and a iris radiolucent. This is the reason why chest x ray appears black. Bronchus is having its own blood supply. And blood is radio-opaque and can be seen on x ray. So any pathology where wall of bronchus is inflammed, edamatous or blood supply in the vessels is increased than they (bronchovascular) are prominent and visible on chest x ray. Common causes for prominent bronchovascular markings (BVM) are viral infection, bronchitis, in normal individual when x ray is taken in expiratory phase, smokers etc. Since you are asymptomatic, possibility of bronchitis or viral infection is very less. And hence you declared fit despite of prominent BVM because this can be seen in normal individual also. Hope I have solved your query. Wish you good health. Thanks.