It can be because of wide range of causes. Kindly meet a Pulmonologist for further evaliation.

Hi Have you had a similar complaint in the past? Do you have any wheezing or whistling sound when you breathe? Any history of frequent cough, colds, runny nose? Do you have any fever or General weakness, malaise or body ache? You would need to see a local doc for examination. Most likely treatment for your medical condition suggests an obstructive airways disease which would be best treated with some inhaled medicines.