Wheezing may be caused by bronchial asthma, which is caused by the narrowing of the airway and therefore causes labored breathing. This condition is caused by exposure to allergens and requires identification of allergens, avoidance or prevention of exposure to allergens, and treatment with anti-allergy or anti-immune drugs and airway-dilating drugs. Wheezing may also be caused by cardiogenic disease or pulmonary stasis, and should be treated with diuretics and airway-dilating medications to reduce the load on the heart. It may be due to severe pneumonia that affects the blood exchange, and therefore the wheezing may occur.