Wheezing is a high-pitched whistling sound during breathing. It occurs when air moves through narrowed breathing tubes in the lungs.

Causes :

Asthma, Breathing a foreign object into the lungs, Bronchiectasis, Bronchitis, Emphysema (COPD), especially when a respiratory infection is present, Gastroesophageal reflux disease, Heart failure, Insect sting that causes an allergic reaction, Medications, Pneumonia, Smoking, Viral infection.