The conscious awareness of the labored breathing or air hunger in conditions other than heavy exercise.

Dyspnea is critical to understand because it is common to many of the pulmonary diseases and is often the predominant and at times an overwhelming symptom which greatly alters or effects the lifestyle of patients with lung disease.

Breathing is typically an unconscious activity and a common method to induce the sensation of dyspnea is breathing Breath-holding.


Afferent Signals Involved

The symptom of dyspnea is one that relates to the entire control system of respiration. In the biggest picture, dyspnea can be related to difficulty getting mitochondria to undergo oxidative phosphorylation. Both the adequate delivery of oxygen and adequate removal of carbon dioxide relate to the absence or development of dyspnea.

Both of these chemical drives to breathe may directly and proportionally increase dyspnea.

Mechanoreceptors of the Respiratory Muscles and Chest Wall
These receptors (particularly the muscle spindles) are fairly well known and understood to mediate dyspnea.

Lung Receptors



Central Processing of these Signals

No simple single physiologic mechanism can account for the various clinical situations in which dyspnea occurs. In addition, there is a widely varying degree of dyspnea for similar degrees of lung or heart disease across individuals. It is felt that both contextual and behavioral influences play an important role in the degree of dyspnea.



Heart failure

Lung diseases

Anxiety state: Multiple sighs

Therapeutic Interventions

The optimal therapy is to treat the cause. Often the cause is untreatable and in that situation the following have been tried