Prevention of altitude illnesses falls into two categories, proper acclimatization and preventive medications. Below are a few basic guidelines for proper acclimatization.
• If possible, don't fly or drive to high altitude. Start below 10,000 feet (3,048 meters) and walk up. ACCLIMATE AT 10k FOR A FEW DAYS BEFORE GOING HIGHER.
• If you do fly or drive, do not over-exert yourself or move higher for the first 24 hours.
• If you go above 10,000 feet (3,048 meters), only increase your altitude by 1,000 feet (305 meters) per day and for every 3,000 feet (915 meters) of elevation gained, take a rest day.
• "Climb High and sleep low." This is the maxim used by climbers. You can climb more than 1,000 feet (305 meters) in a day as long as you come back down and sleep at a lower altitude.
• If you begin to show symptoms of moderate altitude illness, don't go higher until symptoms decrease ("Don't go up until symptoms go down").
• If symptoms increase, go down, down, down!
• Keep in mind that different people will acclimatize at different rates. Make sure all of your party is properly acclimatized before going higher.
• Stay properly hydrated. Acclimatization is often accompanied by fluid loss, so you need to drink lots of fluids to remain properly hydrated (at least 3-4 quarts per day). Urine output should be copious and clear.
• Take it easy; don't over-exert yourself when you first get up to altitude. Light activity during the day is better than sleeping because respiration decreases during sleep, exacerbating the symptoms.
• Avoid tobacco and alcohol and other depressant drugs including, barbiturates, tranquilizers, and sleeping pills. These depressants further decrease the respiratory drive during sleep resulting in a worsening of the symptoms.
• Eat a high carbohydrate diet (more than 70% of your calories from carbohydrates) while at altitude.
• The acclimatization process is inhibited by dehydration, over-exertion, and alcohol and other depressant drugs.
• Diamox (Acetazolamide) allows you to breathe faster so that you metabolize more oxygen, thereby minimizing the symptoms caused by poor oxygenation. This is especially helpful at night when respiratory drive is decreased. Since it takes a while for Diamox to have an effect, it is advisable to start taking it 24 hours before you go to altitude and continue for at least five days at higher altitude. The recommendation of the Himalayan Rescue Association Medical Clinic is 125 mg. twice a day (morning and night). (The standard dose was 250 mg., but their research showed no difference for most people with the lower dose, although some individuals may need 250 mg.) Possible side effects include tingling of the lips and finger tips, blurring of vision, and alteration of taste. These side effects may be reduced with the 125 mg. dose. Side effects subside when the drug is stopped. Contact your physician for a prescription. Since Diamox is a sulfonamide drug, people who are allergic to sulfa drugs should not take Diamox. Diamox has also been known to cause severe allergic reactions to people with no previous history of Diamox or sulfa allergies. Frank Hubbell of SOLO recommends a trial course of the drug before going to a remote location where a severe allergic reaction could prove difficult to treat.
Diamox, a drug often used in the treatment of the eye condition glaucoma, is also useful in the prevention of Acute Mountain Sickness (AMS). AMS occurs commonly during visits to 3000-4500m and may cause a severe headache, exhaustion and general feelings of illness. In rare cases (but sometimes even at these altitudes), the condition progresses to cause more serious problems that are potentially fatal – High Altitude Pulmonary and Cerebral Oedema (HAPE & HACE).
Diamox reduces the headache of AMS and helps the body acclimatise to the lack of oxygen - it also probably reduces the incidence of the complications of AMS mentioned above (HAPE &HACE). Whether or not one takes Diamox is obviously a matter of personal choice - travel to high altitudes is quite possible without it. I do not recommend the drug as a routine treatment, though there is variation of opinion about this many people choose to use it if travelling quickly to altitude (eg. if flying into Lhasa).
How to take Diamox
If you decide to use the drug, I suggest Diamox 125mg (half of one tablet) is taken twice daily as a trial at sea level for two days several weeks before a visit to altitude. Assuming no unpleasant side effects are experienced, take the drug in the same dose for three days before staying at 3500m and thereafter for two or three days until you feel acclimatised, for about five days in all.
Like all drugs, Diamox may have unwanted side effects. Tingling of the fingers, face and feet is the commonest, but this is not a reason for stopping the drug unless the symptoms are intolerable. Dizziness, vomiting, drowsiness, confusion, rashes and more serious allergic reactions have all been reported but are unusual. In exceptional cases, the drug has caused more serious problems with blood formation and/or the kidneys. Those who are allergic to the sulphonamide antibiotics may also be allergic to Diamox.
More commonly, the drug makes many people (including me!) feel a little "off colour"; carbonated drinks and beer also taste strange when you are taking Diamox.
Some individuals no matter what they do have Altitude Illnesses issues....you may be one of them.