Lung Disease & Respiratory Health Center

Understanding Wheezing -- the Basics

What Is Wheezing?

Many people with respiratory allergies know that bouts of wheezing often come with the arrival of hay fever season. Mild wheezing may also accompany respiratory infections such as acute bronchitis and may be experienced by patients in heart failure and by some with emphysema (or chronic obstructive pulmonary disease, COPD). But the characteristic whistling sound of wheezing is a primary symptom of the chronic respiratory disease asthma.

A variety of treatments are available to help alleviate wheezing. You should be regularly monitored by a doctor if you have asthma, severe allergies, chronic bronchitis, emphysema, or COPD. Evaluation by a specialist such as an allergist or pulmonologist may also be recommended in some cases.

What Causes Wheezing?

The whistling sound that characterizes wheezing occurs when air moves through airways that are narrowed, much like the way a whistle or flute makes music. In asthma, this airway narrowing is due to inflammation and spasm of the muscles in the wall of the airways.

Wheezing is usually the result of one of the following health problems:

• Asthma
• Allergic reactions to pollen, chemicals, pet dander, dust, foods, or insect stings
• Acute or chronic bronchitis, which can produce excess mucus in the respiratory tract and cause the lungs' passageways to become blocked

Less commonly, wheezing may also be caused by these health problems:

• Cystic fibrosis
• Obstruction from a foreign body which has been inhaled (such as a coin)
• A tumor in the lungs
• Congestive heart failure (usually in older adults)