wavelength waveÂ·length (wÄv'lÄngkth', -lÄngth') n. Symbol Î» The distance between one peak or crest of a wave of light, heat, or other energy and the next corresponding peak or crest.
Causes: Emphysema: The number one cause of emphysema is smoking. Other contributing factors in its development or exacerbation (increase in severity) include long-term exposure to other lung irritants, such as air pollution, chemical fumes, or dust.
These cases result in usually painless swelling of the face and neck, with an immediate onset, the crepitus (crunching sound) typical of subcutaneous emphysema, and often with subcutaneous air visible on X-ray. One of the main causes of subcutaneous emphysema, along with pneumothorax, is an improperly functioning chest tube.