can occur due to some old infection but may also just be non-specific at his age (assuming he is above 60 years or so). This need not be a cause for worry, especially if he has no cough
. If he has these symptoms, it is probably a good idea to meet a chest physician.
Increase in vascular marking is again not very specific at his age. It may also occur if the Xray has been taken in an expiratory phase or exposure was inadequate (technical factors). Often such X rays are reported as 'increased bronchovascular markings', summarizing the two.
Overall, there seems to be nothing much to worry about on your X ray. However, if his shortness of breath
is severe, persistent or interfering with daily functions, it would be advisable to take the opinion of a chest physician.