Thanks for your question on Healthcare Magic.
I can understand your concern.
Burning sensations in lungs especially on exertion (walking up Hill) is mostly seen with inflammation of the airways (
bronchitis).
You are more than 60 years of age and having history of
smoking, so you are at risk of development of bronchitis.
So we should definitely rule out bronchitis for your symptoms.
So
consult pulmonologist and get done
1. Clinical examination of respiratory system
2. PFT (pulmonary function test).
PFT will not only diagnose bronchitis but it will also tell you about severity of the disease and treatment is based on severity only.
You will need inhaled
bronchodilator and inhaled
corticosteroids (ICS) on the basis of PFT report.
Don't worry, you will be alright with all these.
Hope I have solved your query. I will be happy to help you further. Wish you good health. Thanks.