Acute mountain sickness (AMS) is a condition in which the body is essentially starved of oxygen from low air pressure and body functions suffer accordingly. Symptoms vary widely from a mild annoyance to life threatening, involving the lungs, brain, muscles, heart and nervous system. Usually this is only experienced at elevations above 8,000 feet (2,438 M), but can occur at lower elevations as well. In general the best response is to descend elevation as quickly and safely as possible, but if mild, some can overcome AMS with a simple rest break. While somewhat rare at American altitudes, fluid can begin collecting around the lungs/brain causing pulmonary/cerebral edema. A condition that could very well be life threatening. Luckily in Colorado most of our summit trails are up and down making rapid descent easier.

Recognizing symptoms in yourself, as well as others in your group, will do much to make your hikes safer (we all know that mountain will still be there). Usually the first thing a person notices is a headache. This can also be a symptom of dehydration, but when tacked on to other symptoms AMS should be suspected.

Mild/Moderate symptoms:
• Loss of appetite
• Nausea/vomiting
• Disorientation, feeling dizzy or light headed
• Drowsiness
• Short of breath while exerting
• Shallow breathing, difficulty inhaling deeply
• Fatigue and weakness
• Rapid pulse that doesn't slow at rest
• Bloodshot eyes *my own experience*

More severe symptoms:
• Blueish tint to skin/gums/eyes
• Deep, dry persistent cough
• Tightness or pains in chest
• Coughing blood
• Confusion
• Pale skin
• Staggering, stumbling or difficulty walking straight
• Headache that does not respond to treatment
• Short of breath even after resting
• Unconsciousness/fainting

There are products such as Diamox that are meant to prevent/treat mild symptoms and induce heavier breathing. One side effect is increased urination that could naturally lead to dehydration if not accounted for.

Otherwise, the best preventatives are more of a management system making sure the body is ready for and adjusted to higher altitudes. Spending the two days before a hike drinking more water and increasing carbohydrate intake can help. But adjusting to higher altitudes is best done by getting there. Coming from the front range of Colorado (appx 4,500'-5,500'), I start by making an effort to clear 10,000' while hiking and spend that night at 9,000'. Then the next two weekends are easily attainable 12,000' plus mountains. Working up to this point is part of my system and I have the added advantage of being able to actually do this within a month. After that, the body responds by creating more red blood cells on a regular basis to carry the lower concentration of oxygen around the body (also makes for thicker blood that the circulatory system must deal with). By reaching alpine altitudes weekly, the increased red blood cell count remains constant throughout the hiking season. Not to mention the superman breathing abilities at lower elevations.



Altitude Sickness & Dogs:

Let me preface this section by saying that information on this subject is scattered and speculative at best. So take this with a grain of salt as it is based upon my own observations and conclusions.

As with humans, I believe that the lower air pressure at high altitudes has the same oxygen starving effects on dogs. The problem is that dogs don't really give us a heads up that they might have a headache. Luckily, using baseline information changes can help in making an up or down decision easier. Since I have never seen severe symptoms in dogs first hand, these are the things that I would be looking for on any upper elevation hike:

• Slightly cocked head while walking
• Pawing/scratching repeatedly at one side of the head
• Dry and tacky gums
• Bloodshot eyes
• Swelling tongue
• Blueish coloring to the gums, tongue or inner eyelids
• Coughing
• Hesitation in movements, taking several quick tries for one step
• Fast breathing with heavy drool
• Loss of appetite (my dogs have yet to turn down a summit lunch and it would worry me if they did)
• Rapid pulse that does not diminish with rest
• Rapid breathing that does not diminish with rest


Happy trails and clear sky summits to all!