Hi ! Some of the countries have got very stringent rules of medical fitness for visa, specially if a person from a region where tuberculosis
is common applies for it. Many a times, even though you might not have suffered actually from tuberculosis, you might have got an overt infection in your lungs/lymph
nodes which has subsided due to your good immunity, but might have left a scar with calcification in your lungs which is now detected in the X ray
of chest. If the rules are so stringent, it may not be possible for you to clear medically for the visa. Good luck.