Wheezing is a high-pitched whistling sound produced by air flowing through narrowed breathing tubes, especially the smaller ones deep in the lung. It is a common finding in asthma and chronic obstructive pulmonary disease (COPD).

The clinical importance of wheezing is that it is an indicator of airway narrowing, and it may indicate difficulty breathing.

Wheezing is most obvious when exhaling (breathing out), but may be present during either inspiration (breathing in) or exhalation.

Wheezing most often comes from the small bronchial tubes (breathing tubes deep in the chest), but it may originate if larger airways are obstructed or in certain cases of vocal cord abnormalities.

• Asthma
• Bronchiectasis
• Bronchiolitis
• Bronchitis
• Gastroesophageal reflux disease
• Viral infection, especially in infants younger than 2 years old
• Pneumonia
• Emphysema (COPD), especially when a respiratory infection is present
• Smoking
• Insect sting which causes an allergic reaction
• Medications (many asthmatics wheeze after taking aspirin)
• Inhalation of foreign matter into the lungs
• Heart failure (cardiac asthma)

• Take all of your medications, especially respiratory inhalers, as directed.
• Exposure to moist, heated air (such as through a vaporizer or in a hot shower) may help alleviate some symptoms.

• Wheezing is occurring for the first time
• Wheezing is associated with significant shortness of breath, bluish skin color, or mental status changes
• Wheezing is a recurrent, unexplained problem
• Wheezing is caused by an allergic reaction to a bite or medication

If wheezing is severe or is accompanied by severe shortness of breath, you may have to go directly to the nearest emergency department.

The medical history will be obtained and a physical examination performed.

Medical history questions documenting wheezing in detail may include:

• When did the wheezing begin?
• How long does it last?
• Does it occur often? Daily?
• At what time of day does it occur?
• Is it worse at night or in the early morning?
• What does the wheezing sound like?
• Does it make breathing difficult?
• Does it require stopping all physical activity?
• Does it resolve without treatment?
• What seems to cause it?
  • Eating certain foods?
  • Taking certain medications?
• What makes it worse?
  • Exercise?
  • Stress?
  • Exposure to pollens, insects, dust, chemicals (perfumes, cosmetics)?
  • Exposure to cold air?
  • Cold or flu?
• What helps relieve it?
  • Rest?
  • Medications such as bronchodilators?
• What other symptoms are also present?
  • Is there a fever?
  • Is there coughing?
  • Is there swelling of the lips or tongue?
  • Is there panic or confusion?
  • Is there loss of voice?
  • Is there loss of consciousness?
  • Is there a bluish color to lips or nailbeds?
  • Is there nasal congestion?
  • Are there puffy, red eyes?
  • Is there an insect bite?
• Has there been an episode of choking?
• Is there a history of asthma or allergies?
• What medications are being taken?
• Has there been exposure to tobacco smoke?
• Has there been a recent illness?

The physical examination may include listening to the lung sounds (auscultation). The possibility that foreign material has been swallowed may also be investigated in small children.

Diagnostic tests that may be performed are:

• Chest x-ray
• Pulmonary function tests
• Blood studies, possibly including arterial blood gases

Treatment:

Drugs to relieve narrowing of the airways, such as albuterol, are usually given by inhalation. Hospitalization may be required if the patient's breathing is particularly difficult, or if close observation by medical personnel, intravenous medications, supplemental oxygen are required. In any case, the patient will need to be closely watched.

If a diagnosis is made related to wheezing such as asthma or COPD, further action to treat and manage the condition will be needed.