Unlike alcohol, the onset and disappearance are near instantaneous. A diver may be quite clear-headed at 20 meters, and yet giddy and silly at 30 meters. Ascending to 20 meters will almost instantly clear the head. High pressure nervous syndrome (HPNS)
Barotrauma
Barotrauma is injury caused by pressure effects on gas spaces. This may occur during ascent or descent. The ears are the most commonly affected body part. The most serious injury is lung barotrauma, which can result in pneumothorax, pneumomediastinum, pneumopericardium, subcutaneous emphysema, and arterial gas embolism. All divers, commercial air travelers, people traveling overland between different altitudes, and people who work in pressurized environments have had to deal with some degree of barotrauma effect upon their ears, sinuses, and other air spaces. At the most extreme, barotrauma can cause ruptured eardrums, bleeding sinuses, exploding tooth cavities, and the lung injuries described above. This is the reason why divers follow a procedure of not holding their breath during ascent. By breathing continuously, they keep the airways open and avoid pressure differences between their lungs and ambient pressure. Arterial gas embolism (AGE)
Arterial gas embolism (AGE) is a complication of lung barotrauma of ascent. It occurs when breathing gas is introduced to the circulation on the arterial side via lung over-pressure trauma. AGE can present in similar ways to arterial blockages seen in other medical situations. Affected people may suffer strokes, with paralysis or numbness down one side; they may suffer heart attacks; they may suffer pulmonary embolism with shortness of breath and chest pain.
Worry refers to the thoughts, images, emotions, and actions of a negative nature in a repetitive, uncontrollable manner that results from a proactive cognitive risk analysis made to avoid or solve anticipated potential threats and their potential consequences. Introduction
Psychologically, worry is part of
Perseverative Cognition (a collective term for continuous thinking about negative events in the past or in the future). As an emotion "worry" is experienced from anxiety or concern about a real or imagined issue, often personal issues such as health or finances, or external broader issues such as environmental pollution, social structure or technological change. It is a natural response to anticipated future problems. Excessive worry is a primary diagnostic feature of generalized anxiety disorder, but also is pervasive in other psychological disorders, like schizophrenia. Most people experience short-lived periods of worry in their lives without incident; indeed, a mild amount of worrying have positive effects, if it prompts people to take precautions (e.g., fastening their seat belt or buying insurance) or avoid risky behaviors (e.g., angering dangerous animals, or binge drinking), but with excessive worrisome people they overestimate future dangers in their assessments and in its extremities tend to magnify the situation as a dead end which results stress. Overestimation happens because analytic resources are a combination of external locus of control, personal experience and belief fallacies.