Prevent Altitude Sickness

Whether you are gearing up for a trek in the Himalayas or warming up for snowboarding in the Rockies, you should be prepared for the possible onset of altitude sickness, otherwise known as acute mountains sickness (AMS) or "soroche". High altitudes are stressful on the body, and decrease in oxygen levels up high can produce debilitating effects and ruin your holiday.

• Drink plenty of water. What you might think is altitude sickness might actually be dehydration, caused by the higher rate of water vapor lost from the lungs at higher altitudes. Avoid caffeine and alcohol, as these can increase the likelihood of dehydration. If it's humid and you're losing a lot of water through perspiration, maintain an electrolyte balance with sports drinks targeted specifically for this purpose.
  
  If you have a headache, drink one liter of fluid, and take some acetaminophen (brand name: Tylenol). If the headache disappears completely and rapidly, and you have no other symptoms of AMS (see the next step), you're probably dealing with dehydration rather than altitude sickness
• Look out for the symptoms of altitude sickness. 20% of people develop mild symptoms at altitudes between 1920 to 2960 meters (6,300 to 9,700 feet). If you know you're getting enough water, the symptoms of altitude sickness will manifest themselves about 6 to 10 hours after ascent over 2000 meters (6,500 feet) above sea level and are comparable to those of a severe hangover:
  
  

1. Loss of appetite
2. Nausea or vomiting
3. Fatigue or weakness
4. Dizziness or light-headedness
5. Insomnia
6. Pins and needles
7. Shortness of breath upon exertion
8. Persistent rapid pulse
9. Drowsiness
10. Peripheral edema (swelling of hands, feet, and face) 

• Get emergency treatment if you observe life-threatening symptoms. Extreme altitude sickness can result in fatal conditions like high altitude pulmonary edema (HAPE) (fluid in the lungs) and high altitude cerebral edema (HACE) (swelling of the brain), both occurring in up to 2% of people adjusting to altitudes above 2700 m (9,000 feet). If any of the following symptoms are observed, medical treatment is necessary and an immediate descent should be made:
  
  
• persistent dry cough
• fever
• shortness of breath even when resting
• headache that does not respond to analgesics
• unsteady walking
• increasing vomiting
• gradual loss of consciousness

• Follow the "golden rule" - climb high, sleep low. Once you've made your way up past 3,000 metres (10,000 feet), do not ascend more than 300 metres (1,000 feet) per day to sleep. You can climb as high as you want, just make sure that you come back to a base camp that's no more than 300 m (1,000') higher than your previous night's sleeping elevation. This is a useful guideline to keep in mind if you're driving to a high altitude, as well.
• Accelerate the acclimatization process if necessary. If there is not enough time to follow the golden rule, such as if you're flying to a destination that is several hundred metres (or thousand feet) above your departure site, there are ways to speed up acclimatization and reduce the symptoms of altitude sickness once you're there.
  
  
• Simulated altitude equipment that produce hypoxic (reduced oxygen) air. Portable hyperbaric chambers are especially useful if inclement weather or other factors could make the climb or drive down to base camp impossible.
• Acetazolamide, medication sold under the trade name Diamox Since it causes increased urination, drink sufficient fluids and do not consume alcohol while taking this drug. This is likely to cut the recovery time in half.
• Coca leaves, used by indigenous cultures of the South American Andes mountain range for centuries. However these are illegal in several countries.
• Ginkgo Biloba, an inexpensive herbal supplement used for mental clarity and increased circulation, has been proven to speed acclimatization to altitude and lessen the effects of Acute Mountain Sickness in several clinical and on-location studies, without incurring any of the side effects of Diamox. Recommended dosage is 120mg per day, two weeks before arriving at altitude, then 120mg per day while at altitude.
• Oxygen enrichment in climate-controlled rooms (offered by some hotels)
• Gamow bag, a portable plastic pressure bag inflated with a foot pump that can reduce the effective altitude by as much as 1,500 meters (5,000 feet)

• Take it easy. The last thing you would want to do is to overexert yourself. It is harder to breathe at higher altitude and even if you are fit, you can still feel the effects if you push yourself too hard too quickly. Resting at the altitude at which you became ill is often the most effective remedy for altitude sickness (other than descent). You'll usually feel better in 1-2 (or up to 4) days.

TIPS:

• Train physically prior to the trip. While this does not guarantee an easier time when up high, it can enhance your lung ability to cope with the challenges of high elevations
• Do not compete amongst each other. Different people acclimatize at different rates.
• If you live at or near sea level, you're more likely to experience altitude sickness, so be prepared.
• Eat lots of carbohydrate.
• If you do develop altitude sickness, take dexamethasone