Wheezing is a high-pitched sound heard when air passes through a narrowed passageway. Wheezing is caused by spasms, swelling, mucus, or inflammation in the medium and large air passages in the lungs (bronchi). Wheezing may be heard when you breathe in or out. Often wheezing begins or becomes worse at night.
Inflammation of the airways or the lung tissue itself can cause shortness of breath. Spasm and swelling of the airways or mucus trapped in the air passages of the lungs can also reduce airflow and cause wheezing. Examples of diseases that may cause wheezing include:
Infections of the
lung or
lower airway
may impair lung function or may cause wheezing. If fever
and cough are also present, a lung or lower airway infection may be present.
WebMD Medical Reference from Healthwise