Wheezing is a whistling or squeaky sound in your chest when you breathe, especially when you exhale. It is one of the telltale signs of asthma.
Swelling or narrowing of your throat or the airways to your lungs can cause wheezing. It can also result in shortness of breath, because your lungs can’t hold as much air when they are affected by swelling or mucus buildup.
Although asthma and chronic obstructive pulmonary disease are most often associated with wheezing, an allergic reaction is another common cause of these symptoms.
Sometimes children experience wheezing, but it is not always a sign of asthma. A lung infection can create wheezing in children younger than 5. And wheezing and shortness of breath can sometimes be symptoms of a cold in children with a family history of allergies.
Wheezing is often, but not always, related to an asthma attack. During an asthma attack, the airways become more narrow. At first, the person wheezes when breathing out, but as the attack gets worse, the wheezing might happen when breathing in. During a severe asthma attack, there might not be any wheezing because not enough air is moving through the airways.