Asthma is a disease characterized by inflammation of the airways, also known as the “bronchial tubes”, of lungs. This, as well as the tightening of the bronchial muscles and the excess mucus produced by the airways, constricts the bronchial tubes, making it difficult for air to pass through. When air flows through these constricted bronchial tubes, a whistling sound is produced. This whistling sound is known as “wheezing”. This sound differs from rattling or gurgling.

Although wheezing can occur both during breathing in (inhaling) and out (exhaling), it is more pronounced during exhaling. It must distinguished from a stridor, which is a loud sound heard during inhalation.

However, even if the airways become narrow due to inflammation, the obstruction of the flow of air may produce a wheezing sound that is impossible to hear. That’s why many patients with asthma do not have wheezing as one of their symptoms. Usually, infants, young children and adolescents suffer from wheezing due to their small airways.

That’s why absence of wheezing does not confirm that the person does not have asthma. The person would instead show other symptoms such as chest tightness, coughing, trouble breathing and shortness of breath. In almost all cases, a lung function test is carried out to diagnose asthma correctly.