Sir 28 days ago i wake up in night with shortness of breath. my chest x-ray is good. and doctor suggest me myteka 10mg tablet but i still have problem?

?allergy: Your doctor feels you have asthma (based on his choice of medicine) and that's statistically most likely. Do you wheeze or cough when you wake up? If so, try adding an albuterol inhaler. Asthma doesn't show up on a chest x-ray, which would be normal. Have your Dr. draw a BNP to rule out (an unlikely) heart issue. Alternatively, do you feel anxious? Hyperventilation/anxiety can do this too.

Heart check up: If you mean you are sleeping and each night you wake up with shortness of breath, e.g. making you sit on the side of the bed to feel better, you will need a cardiac evaluation. This is call paroxysmal nocturnal dyspnea (PND) and may be a sign that your heart cannot handle the increased return of blood when you raise your legs at night. If this was a one time episode, check back with your doctor.