Health Matters: What you need to know about altitude sickness
Q: We are lucky enough to be planning a vacation in the Rockies. I'm concerned about the effect of the altitude on us. Any suggestions?
A: Lucky you! But you're right that since places like the Rocky Mountains are 12,000 feet above sea level, the reduced level of oxygen in the air there can cause health problems, especially for those with preexisting heart, lung, or other health conditions.
Called acute mountain sickness (AMS), this condition is associated with a variety of problems with normal body functioning, including too little oxygen in the blood and tissues, salt and water retention in the body, and over-activity of the nervous system. These lead to symptoms like nausea and vomiting, headache, dizziness and fatigue. In most cases, the symptoms subside on their own within a day or two. If symptoms do not decrease, using supplemental oxygen or descending to a lower altitude is required.
The frequency of AMS increases with altitude — about a quarter of people will experience symptoms when at 11,500 feet or higher, and more than half will do so above 20,000 feet or so. The two major determinants of who gets AMS are how rapidly one ascends to the high altitude, and whether you have had AMS previously. Thus, one way to reduce the risk of AMS is to acclimate to higher altitudes by ascending gradually, with rest stops at lower altitudes especially for sleep periods. Drinking plenty of fluids and taking a medication called acetazolamide also may help. Be sure to check with your doctor to see if any special precautions are needed. Enjoy the trip!
Q: I know that exercise is good for you, but what are the associated risks of participating in sports? I just read about an unfortunate fellow who died of cardiac arrest while jogging.
A: While musculoskeletal injuries are common for athletes of many different sports, it turns out that the risk of sudden cardiac arrest while participating in sporting events is really low. A large recent study from Canada found that the rate was about one per 130,000 years of athletic participation, meaning that in any one year, we would find only one sudden cardiac arrest event in a field of 130,000 athletes.
One of the interesting findings from the study was that blockages due to cholesterol deposits in the heart arteries ("coronary artery disease") was not an especially common cause of sudden cardiac arrest, although the study was limited to people 45 years of age or fewer. Most of the cases had no obvious heart problem that could be identified after the arrest, and the sudden cardiac arrest was attributed to an irregular heart rhythm.
The implication of these findings is that pre-exercise screening for a heart condition that might predispose the person to sudden cardiac arrest likely would not have been very helpful. So at least for people aged 45 years or younger who are otherwise healthy, have no history (either personal or in their families) of health issues related to exercise, are taking no medications, and have no symptoms when exercising, the risk of sudden cardiac arrest is typically quite low.
Wynne is vice president for health affairs at UND, dean of the School of Medicine and Health Sciences, and a professor of medicine. He is a cardiologist by training.
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