Just the mention of Altitude Illness conjures images of climbers struggling up distant peaks with unpronounceable names. But let me ask you one question. What state has the highest average elevation…? Wrong. It’s Colorado. Since mountain sickness occurs as low as 8,000 feet it affects many more casual visitors such as hikers, skiers, hunters than mountain climbers. Fortunately knowing just a little about this illness –and how to avoid it- can keep your Rocky Mountain High from bringing you down.

Normal affects of altitude

At altitude oxygen concentration is the same as sea level, 21%. What changes is the pressure that helps drive that oxygen thru the lungs and into our blood. So as one ascends higher and higher each breath delivers less oxygen, less oxygen to muscles, to the digestive system and -more importantly- less oxygen to the heart, lungs and brain. Most people don’t notice affects of less oxygen until at least 8,000’ but most will notice at least some effect above that. If you’ve gone for a hike, skiing or even an easy walk upon arriving at altitude you’ve probably noticed feeling short of breath. Since there’s less oxygen, the body works harder to get it. You breath both faster and deeper and become short of breath more easily, especially with exertion. This shortness of breath should resolve quickly with rest.

Another normal change at altitude is a changed breathing pattern at night. This "periodic" breathing is a cycle with a burst of fast breathing followed by a period of breath holding lasting up to 10-15 seconds. Remember this is normal –actually quite common- but can be alarming in persons who wake up and realize their neighbor is not breathing, or to the person who wakes up during the breath-holding phase and knows he stopped breathing.

Acclimatization – How the Body Adapts to Altitude

Given time the body is quite capable of adjusting to higher altitudes as permanent residents living over 17,000’ in the Andes and Himalayas have proven. The process of acclimatization consists primarily of increased respirations and an increase in the concentration of red blood cells –those are the ones that carry oxygen. As red blood cell concentration increases there may be fluid shifting out of the blood stream causing swelling, especially noticed in hands, feet and face.

Visitors to altitude, however, are susceptible to illness. The most important predisposing factors that determine whether you will get sick are; rate of ascent, altitude reached and sleeping altitude. A high country visitor from a low altitude who arrives quickly by air or auto is especially at risk. Significant heart or lung disease may also contribute. An individuals response will even vary, doing fine on one trip but getting altitude illness on another with identical itineraries.

I’m too physically fit to get altitude sickness. Right?

Wrong. Individuals vary widely in their susceptibility to altitude. Fit persons may push themselves harder and higher than others and may be more likely to develop illness. Some people acclimatize quickly and can ascend more rapidly. Others may go slower and still become ill.

I’ve climbed 14’ers. Sure I could feel the altitude but I kept going and did fine.

Quick ascent followed by quick descent is better tolerated than a prolonged stay when spending the night at altitude. Persons acclimated to even 5,000 or 6,000 feet have a huge head start over those coming from low altitudes. Studies in Alaska showed that between 70 – 100 % rate of altitude illness for persons acclimated to sea level and have rapidly ascended to 14,000’. It is normal to feel some shortness of breath at altitude but you should not continue ascent at all if you have any signs or symptoms of altitude illness.

Altitude Illness Defined

Altitude Illness is what happens when the body –more specifically the brain or the lungs- has insufficient time to compensate for the lower amount of oxygen available to it. Symptoms typically begin within 6 to 10 hours but can start as quickly as one hour.

Poor acclimatization causes swelling in the brain. This feels a bit like a hangover with HEADACHE, nausea and possibly insomnia, loss of appetite and fatigue –above 8,000 feet. These symptoms may be hard to distinguish from the normal effects of a hard day of work or play. Try drinking a quart of water and taking ibuprofen or Tylenol and rest. If symptoms persist descent is suggested -1,000 to 2,000 feet.

If ascent is continued HACE can become life threatening; remember we’re talking brain swelling here. 2 symptoms define severe HACE as brain swelling progresses; ATAXIA -the sick person walks with a staggering gait as if intoxicated, and changes in mental status such as confusion, poor decision-making or irrational behavior. Severe HACE is truly a life threatening condition and immediate descent is necessary. The victims should be assisted or carried to a lower elevation immediately, without waiting for rescue, ideally to the last elevation where they woke up feeling well, or at least 1,500 feet. Ill persons at altitude should not be left alone.

Fortunately HACE progresses relatively slowly and rarely becomes severe unless ascent is continued in the presence of symptoms.

The other major body system vulnerable to inadequate oxygen from altitude is the lungs. Capillaries providing blood to the lungs swell and become leaky, further complicating the process of breathing. Of course this just makes shortness of breath worse.

Fluid in the lungs is called pulmonary edema. We know that shortness of breath with exertion at altitude is normal. For a victim of HAPE, however, this does not resolve with rest. The victim may develop a dry cough or complain of continued difficulty with breathing or prolonged recovery time even after long rest periods. You may notice an increase in respiratory rate, normally 12 to 20 per minute. This person may fall behind the rest of the group and may not be able to sleep lying down as congestion in the lungs make breathing more difficult.

Unlike HACE, which develops slowly, HAPE can develop quite rapidly –minutes to hours- and unlike HACE, HAPE is by definition life threatening. The cough of HAPE is caused from fluid in the lungs. As fluid increases the cough will worsen. Amounts of clear or blood tinged sputum develops which can progress into gurgling respirations. Skin color may be pale. This person is clearly in distress.

Descent is the treatment for HAPE, whether it’s convenient or the middle of the night. Upright positioning allows better drainage of fluid. Early identification and descent via auto, horseback, or with the assistance of companions is best since exertion by the victim can make HAPE worse. Descent, under ones own power, should not be delayed if at all possible since this condition worsens so quickly.

Victims of Altitude Illness generally recover quickly, requiring a day or two of rest for complete recovery. Once the symptoms have resolved cautious re-ascent is possible.

Denial is Common

It’s easy to want to blame about anything else. Often significant money and energy is spent getting into the high country, whether for a major expedition, the family ski trip, or the annual summer backpack adventure or hunting foray. Treatment for altitude sickness means slowing ascent or descending. Both represent a disruption of plans.

Prevention

Respiratory depressants such as narcotic pain medications and sleeping medications should be avoided. Drink alcohol in small amounts. Avoid overexertion. Trips to the high country can be planned to include a night or two at lower elevations, especially for those who live near sea level.

Dehydration can be more problematic at altitude. Increased breathing and dry air contribute to fluid loss requiring more water intake. Electrolyte energy drinks can help make plain water more appealing plus add nutrition. Poor appetite at attitude is common. Simple carbohydrates such as crackers, soups, and candy bars are more easily digested -and more palatable- than foods high in protein or fat.

The best way to avoid altitude illness is to give plenty of time to acclimatize. Plan your trip to spend at least one night at an intermediate elevation below 9,000 feet. On arrival at altitude take it easy for a day or two to give your body time to adjust. Do not continue to ascend if you don’t feel well. Monitor yourself and your friends for any sign of illness and remember the rules:

1. Any illness that develops at altitude should be assumed to be altitude illness until proven otherwise.

2. Do not continue to ascend if you do not feel well.

3. If you are getting worse, go down immediately.

I know "rules were make to be broken" but keeping to these will keep you in the high country longer –and feeling better while you’re there.

John Schwieder is a flight paramedic with San Juan Regional Air Care in Farmington, NM. He is an instructor with Wilderness Medical Associates and a photographer. His collection of wildlife, landscape and adventure photos can be found at www.wilderness.pics.com along with outdoor stories and articles.