$Unique_ID{BRK04010} $Pretitle{} $Title{Mountain Sickness, Acute} $Subject{Mountain Sickness, Acute AMS Mountain Sickness High Altitude Illness Hypoxia Puna Soroche Mareo High Altitude Pulmonary Edema (HAPE) High Altitude Cerebral Edema (HACE) Subacute Infantile Mountain Sickness } $Volume{} $Log{} Copyright (C) 1989 National Organization for Rare Disorders, Inc. 619: Mountain Sickness, Acute ** IMPORTANT ** It is possible that the main title of the article (Acute Mountain Sickness) is not the name you expected. Please check the SYNONYM listing to find the alternate names and disorder subdivisions covered by this article. Synonyms AMS Mountain Sickness High Altitude Illness Hypoxia Puna Soroche Mareo Disorder Subdivisions: High Altitude Pulmonary Edema (HAPE) High Altitude Cerebral Edema (HACE) Information on the following diseases can be found in the Related Disorders section of this report: Subacute Infantile Mountain Sickness General Discussion ** REMINDER ** The information contained in the Rare Disease Database is provided for educational purposes only. It should not be used for diagnostic or treatment purposes. If you wish to obtain more information about this disorder, please contact your personal physician and/or the agencies listed in the "Resources" section of this report. Acute Mountain Sickness is a group of symptoms that may occur in some people who ascend rapidly to altitudes higher than 8200 ft. (2500 m). Major symptoms may include headaches, nausea, vomiting, and insomnia. Symptoms Acute Mountain Sickness may occur during the first 8 to 24 hours after a person reaches a high elevation (altitude). The occurrence, severity, and duration of Acute Mountain Sickness varies with the rate and ultimate height of the climb and with an individual's susceptibility. Headache, poor appetite, nausea, vomiting, tiredness, and poor sleep may occur. There may be abnormal sounds during breathing (rales), bleeding of the retina (light- sensitive layer inside the eye), and excess fluid under the skin (peripheral edema). Decreased urination (oliguria), inability to coordinate voluntary muscle movements (ataxia), and impaired thinking may also occur. Severe (Chronic) Mountain Sickness patients may develop oxygen-deficient tissues (hypoxia) and excessive amounts of red blood cells (polycythemia). Causes Symptoms of Acute Mountain Sickness occur because there is less oxygen at higher altitudes, and the body's tissues receive less oxygen. People may be susceptible to Acute Mountain Sickness if their cells need more oxygen than normal or if they cannot tolerate decreased oxygen levels at high altitudes. People that urinate infrequently are especially susceptible to Acute Mountain Sickness. Affected Population Acute Mountain Sickness affects males and females in equal numbers when they ascend to high altitudes very rapidly. Related Disorders Symptoms of the following disorders can be similar to those of Acute Mountain Sickness. Comparisons may be useful for a differential diagnosis: Subacute Infantile Mountain Sickness is a severe disorder of infants. It may occur when infants are born at low altitudes and then taken to higher elevations. Thickening of the arteries to the lungs and enlargement of their openings may occur. There may also be thickening and enlargement of the cavities of the heart. The following disorders may be associated with Acute Mountain Sickness as secondary characteristics. They are not necessary for a differential diagnosis: High Altitude Pulmonary Edema (HAPE) is a severe complication of Acute Mountain Sickness which involves high levels of fluids, proteins and cells in the lung. Symptoms may include breathing difficulties, coughing, abnormal sounds during breathing, and rapid heart beat. The skin may turn blue or purple (cyanosis). Headaches, vomiting, memory problems, disorientation, loss of consciousness, bleeding of the retina, and excessive fluid in the optic disks (papilledema) may also occur. High Altitude Cerebral Edema (HACE) is a severe consequence of Acute Mountain Sickness which involves extra fluid in the brain. It may occur when the central nervous system is deprived of oxygen. Symptoms may include headaches, inability to coordinate voluntary muscle movements (ataxia), and loss of consciousness. Double vision (diplopia), visual and auditory (hearing) hallucinations, and papilledema may also occur. Therapies: Standard Descending from a high altitude is the most successful treatment for Acute Mountain Sickness. For mild cases, rest, frequent small meals, no alcohol, and acetaminophen for headache may be all that is needed. Dexamethasone, an anti-inflammatory and anti-allergic drug, and the diuretic acetazolamide may be used for more severe cases. To prevent Acute Mountain Sickness , a slow climb, staying 2 to 5 days at a middle altitude (staging), or the use of the drug dexamethasone or acetazolamide may be recommended. Therapies: Investigational Researchers are investigating oxygen therapy and the combination of dexamethasone and acetazolamide for the treatment of Acute Mountain Sickness. This disease entry is based upon medical information available through April 1989. Since NORD's resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder. Resources For more information on Acute Mountain Sickness, please contact: National Organization for Rare Disorders (NORD) P.O. Box 8923 New Fairfield, CT 06812-1783 (203) 746-6518 National Institute of Environmental Health Sciences Public Affairs Office P.O. Box 12233 Research Triangle Park, NC 27709 (919) 541-3345 References CURRENT CONCEPTS: ACUTE MOUNTAIN SICKNESS: T.S. Johnson, et al.; N Engl J Med (September 29, 1988: issue 319(13)). Pp. 841-845. CLINICAL FEATURES OF PATIENTS WITH HIGH-ALTITUDE PULMONARY EDEMA IN JAPAN: T. Kobayashi et al.; Chest (November, 1987: issue 92(5)). Pp. 814- 821. HIGH ALTITUDE CEREBRAL OEDEMA: C. Clarke; Int J Sports Med (April, 1988: issue 9(2)). Pp. 170-174.