altitude sickness

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altitude sickness:

see decompression sicknessdecompression sickness,
physiological disorder caused by a rapid decrease in atmospheric pressure, resulting in the release of nitrogen bubbles into the body tissues. It is also known as caisson disease, altitude sickness, and the bends.
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Altitude Sickness

 

a pathological condition that arises upon ascent to great heights (above 3,000 m) resulting from lowered partial pressure of oxygen in inhaled air. The development of altitude sickness is associated with a disturbance of the function of certain organs and systems, chiefly of the cells of the higher sections of the central nervous system, resulting from oxygen starvation, or hypoxia. At heights under 3,000 m, a healthy person’s oxygen deficiency is compensated for by an increase in pulmonary ventilation (faster and deeper breathing), in blood circulation, and in hemoglobin and erythrocyte count in the blood. Further ascent brings on hypoxia, since the functions of the organism can no longer provide sufficient compensation. A shortage of oxygen in the surrounding air leads to lowered partial pressure of oxygen in the lungs and to lowered oxygen saturation of arterial blood. The major symptoms of altitude sickness include shortness of breath, heart palpitations, dizziness, noise in the ears, headache, nausea, weakness of the muscles, perspiration, blurred vision, sleepiness, and decreased stamina. The symptoms develop in phases, depending on the speed of ascent and on the functional state of the organism. Alcohol, fatigue, and insomnia lower the tolerance for great heights.

Treatments for altitude sickness include descent to a lower altitude, rest, cardiac medicines, and strong tea or coffee. In severe cases, inhalation of oxygen is called for. Inhalation of oxygen from a special apparatus while ascending to great heights prevents altitude sickness. Sports that increase the organism’s demand for oxygen and thus cause hypoxia develop the organism’s resistance to hypoxia. One variant of altitude sickness is mountain sickness. Along with an oxygen deficiency, other factors in mountain sickness are physical exhaustion, cold, and ultraviolet radiation. With acclimatization to the mountain climate, the symptoms of mountain sickness weaken. Relative stabilization of the physiological indexes begins after approximately a three-week stay in the mountains.

N. A. AGADZHANIAN

altitude sickness

[′al·tə‚tüd ‚sik·nəs]
(medicine)
In general, any sickness brought on by exposure to reduced oxygen tension and barometric pressure.

altitude sickness

In general, any sickness brought on by exposure to reduced partial pressure of oxygen and barometric pressure.
References in periodicals archive ?
We regret, therefore, if the brevity of our article and its strong emphasis on safe acclimatisation practices and basic field management of altitude illness have left the misapprehension that we do not advocate the use of acetazolamide where indicated.
Incidence and symptoms of high altitude illness in South Pole workers: Antarctic study of altitude physiology (ASAP).
Prevention strategies should be based on an individual's risk profile (for example, prior history of altitude illness, or having experienced a rapid gain in altitude).
The researchers also found that taking acetazolamide (ACZ), a drug frequently prescribed to prevent altitude illness, can reduce some of the risk factors associated with SHAI.
Additional symptoms that may indicate altitude illness include vertigo, "feeling hung over," thirst, tinnitus (ringing in the ears), nightmares and change in vision with retinal hemorrhage, slowing of speech, excess flatulence, swelling of the hands and feet, and transient global amnesia.
These may help prevent altitude illness but they do have some side effects.
HAPE is a serious and potentially life-threatening manifestation of altitude illness. Up to 15 % of travelers to altitudes over 2,500 m (8,202 ft) will develop HAPE, depending on the traveler's age and sex, and the rate of ascent18.
Altitude illness is common in people ascending to more than 2500 m, especially when the ascent is rapid.
During sojourns at high altitude oxygen saturation measured by pulse oximetry (Sp[O.sub.2]) is widely used to facilitate the diagnosis of high altitude illness at an early state and to assess the individual acclimatization status [1].
Whenever I go to altitude I always carry a small advice book such as this one in my first aid kit to ensure I don't forget anything when diagnosing or treating altitude illness in a trekker, climber or porter