What is Altitude?
Altitude is height above mean sea level. If the sea level in a certain place is 100 feet and you are 250 feet above the ground, your altitude above sea level would be 350 feet, and your altitude above ground level would be 250 feet. We all enjoy the tremendous view from a high summit, but there are risks in going to high altitude, and it’s important to understand these risks. Given time, your body can adapt to the decrease in oxygen molecules at a specific altitude. This process is known as acclimatization and generally takes 1-3 days at that altitude.
How long does acclimatization last?
It varies, but if you were at altitude for a month or more your improved work rates can persist for weeks meaning you still feel fit upon returning to altitude. You still should not ascend faster than normal if you return to sea level for a few days, otherwise you are susceptible to HAPE.
If you have been to 5000m/16,404ft then go down to 3500m / 11,483ft for a few days, returning rapidly to 5000m/16,404ft should cause no problems, i.e. having been to Lobuche and Kala Pattar, and then rested for two days in Namche you should be able to ascend to Gokyo quickly without problems
Sleeping at altitude
Many people have trouble sleeping in a new environment, especially if it changes every day. Altitude adds to the problems. The decrease of oxygen means that some people experience wild dreams with this often happening at around 3000m. Compound this with a few people suffering from headaches or nausea, a couple of toilet visits, a few snorers and periodic breathers, and it takes someone who sleeps like the proverbial log (or very tired trekker) to ignore all the goings on at night in a large dormitory. Smaller rooms are a definite improvement, and tents, although not soundproof are still manage to be relatively peaceful.
Altitude Sickness Information
Individual rates of acclimatization vary enormously but ascending very rapidly and staying there will always result in problems. Altitude sickness often known as Acute Mountain Sickness (A.M.S.) in general may occur when people ascend too quickly normally in altitudes of over 3000 meter. We ensure minimal risk by building in rest days into our trekking itineraries. Most people will feel some affect of altitude, shortness of breath and possibly light headed, which is fairly common. Acute mountain sickness is very different and normally involves a severe headache, sickness and loss of awareness. In almost every potential case there are enough warning signs to take appropriate action.
Our experienced and well trained guides will advise you about any health issues and also altitude sickness while you are on trekking, so you should not worry about it. Before leaving for the trip we suggest to consult with your Medical Doctor and get advice. The following information gives you an idea about high altitude sickness and how to minimize the effects.
Prevention of Altitude Illnesses
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.
- 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 1,640 feet (500 meters) per day and for every 3,280 feet (1000 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 1,640 feet (500 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.
- 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.
- Always remember that the acclimatization process is inhibited by dehydration, over-exertion, and alcohol and other depressant drugs.