What is a wheeze?

A wheeze is the sound generated when air travels
though a breathing passage (airway) that has become
narrowed. The narrowing can be due to mucus secretions
trapped within the airway or to the airway muscles’
constriction or tightening around the airway. The
airway narrowing due to asthma is reversible. Medications
prescribed for asthma help the narrowed airway
return to its normal state. A wheeze is best described
as a high-pitched whistling sound.Wheezing can occur
while breathing in (inspiratory wheezing, during the
inspiratory phase of the breath), while breathing out
(expiratory wheezing, during the expiratory phase of
the breath), or during the entire breath. Asthma is one
of several conditions that can cause wheezing, as
detailed further in the following question. If wheezing
is severe, it can be heard without a stethoscope.
Wheezing in asthma reflects ongoing lung inflammation
and airway narrowing, or bronchoconstriction. The sound
is generated by turbulent flow through constricted airways.
The presence of wheezing in asthma indicates that
the asthma is active, and that more intensive and efficacious
treatment is warranted.Wheezing is never normal
and should never be ignored. If airway narrowing and
inflammation are left untreated, there is a real risk of the
disease worsening, which can become potentially life
threatening.