الفهرس 
Pathophysiology of DyspneaOnly 14 pages are availabe for public view
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Abstract
The respiratory system is dependent upon adequate ventilation to supply oxygen, remove carbon dioxide, and help maintain acid-base homeostasis. Ventilation responds to changes in the arterial carbon dioxide tension (PaCO2), arterial oxygen tension (PaO2), and pH and may be modified in response to a number of mechanical and irritant stimuli arising from various structures within the thoracic cage, and probably from within muscles and joints during exercise.
Broadly viewed, the respiratory control mechanisms respond to input from neural and chemical receptors. Respiratory centers in the brain integrate these inputs and provide neuronal drive to the respiratory muscles, which maintain upper airway patency and drive the thoracic bellows to determine the level of ventilation.
Acute hypercapnia: While acute hypercapnia typically leads to brisk increases in ventilation, dyspnea can result from hypercapnia among ventilator-dependent C1-2 quadriplegics who lack functioning respiratory muscles, and in normal subjects paralyzed with neuromuscular blocking agents.
Acute hypoxemia: Acute hypoxemia is also associated with increases in ventilation and respiratory discomfort. While the data supporting a direct role for hypoxic stimulation of chemoreceptors in the production of dyspnea are less clear than with hypercapnia, it seems likely that hypoxemia can produce breathing discomfort independently of changes in ventilation.
There are many causes of acute dyspnea like:
Angiodema, anaphylaxis, pharyngeal infections, deep neck infections, foreign body and neck trauma
Chest wall:
Rib fractures and flail chest.
Pulmonary
COPD exacerbation, asthma exacerbation, pulmonary embolism, pneumothorax, pulmonary infection, ARDS, pulmonary contusion or other lung injury and hemorrhage.
Cardiac
ACS, ADHF, flash pulmonary edema, high output failure, cardiomyopathy, arrhythmia, valvular dysfunction and Cardiac tamponade.
Neurological
Stroke and neuromuscular disease.
Toxic/metabolic,
Organophosphate poisoning, salicylate poisioning, CO poisoning, toxic ingestion, diabetic ketoacidosis, Sepsis, Anemia and acute chest syndrome.
Miscellaneous
Hyperventilation, anxiety, pneumomediastinum, lung tumor, pleural effusion, intra-abdominal process, Ascites, Pregnancy and massive obesity.
ARDS and pulmonary embolism myocardial infarction pneumothorax and pneumonia consider the most common causes of acute dyspnea.