What Are the Specific Causes of Dyspnea?
The causes of acute dyspnea–that is, shortness of breath that comes on over minutes, include: pneumothorax, or collapsed lung (FIGURE 2), which usually results from trauma to the chest, whether blunt (such as a fall or automobile accident that breaks ribs) or penetrating (such as a stab wound or a gunshot wound), but can also occur “spontaneously.” Spontaneous pneumothorax is actually rather common, and usually results from the rupture of a “bleb,” or abnormal air-filled sac of lung tissue, most often in younger people (age 20-40) who are tall and thin. Traumatic pneumothorax and associated injuries may be fatal, and treatment usually involves inserting a needle and tube into the chest. Spontaneous pneumothorax may or may not require specific treatment and is hardly ever life-threatening; pulmonary embolism, or a blood clot lodged in and blocking one of the arteries supplying blood flow to the lungs (FIGURE 3). Such clots usually originate elsewhere in the body, especially in the legs
