Many of us takes  the precautions we need when we are on our way to high altitude places. Like over from Manali – Leh and further in Ladakh region. If we are riding we get spares for our bikes, warm clothes, recharge our cameras and ipods..etc.

But most of us forget about the most important factor in this reagion which is not to be taken lightly at all as it can be life – threatning I.e AMS (  Acute Mountain Sickness ).

No one can predict who will suffer from AMS and how bad it’ll get. Some people can suffer mildly, some wont even feel it whereas for some it can get real bad. 

It commonly occurs above 2,400 metres (8,000 feet). 

Altitude can be categorized under 3 categories: 

1. High Altitude – 1500 – 3500M (  5,000 – 11,500 feet )
2. Very High Altitude – 3,500 – 5,500m (11,500 – 18,000 feet )
3. Extreme Altitude – 5500m+ ( 18,000 feet above ) 

Here i will try to help you with some more deep information about AMS and how to prevent it :

Causes:  

Acute mountain sickness is caused due to a combination of reduced air pressure and lower oxygen levels at high altitudes. Although the proportion of oxygen in the atmosphere always remains the same (21%), as we go higher the "driving pressure" decreases. The driving pressure depends directly on the barometric pressure, and forces oxygen from the atmosphere into the capillaries of the lungs. Reduced driving pressure results in decreased saturation of oxygen in the blood and throughout the tissues. The main cause of altitude sickness is ascending too rapidly. It may also be caused by going too high and staying there for too long. The human body needs to adapt to the lower air pressure and decreased levels of oxygen – for that it needs a gradual progression (acclimatization). The faster you climb to a high altitude, the more likely you will get acute mountain sickness. Your symptoms will also depend on the speed of your climb and how hard you push yourself.

You are at higher risk for acute mountain sickness if you live at or near sea level or if you had the illness before.

Symptoms :- 

The primary symptom to diagnose altitude sickness is a headache. However, one of dehydration's symptoms is also headache. Therefore, for proper diagnosis, experts say the patient needs to be at a height of at least 2,500 meters (8,000 feet), has a headache, as well as at least one of the signs and symptoms listed below:

• Lack of appetite, nausea, or vomiting
• Exhaustion or weakness
• Dizziness (light-headedness)
• Rapid Pulse
• Insomnia
• Pins and needles
• Shortness of breath
• Feeling sleepy (drowsiness)
• Swelling of the hands, feet and face 

Symptoms generally associated with more severe acute mountain sickness include:

Prevention :

Ascending slowly is the best way to avoid altitude sickness. Avoiding strenuous activity such as skiing, hiking, etc. in the first 24 hours at high altitude reduces the symptoms of AMS. As alcohol tends to cause dehydration, avoiding alcohol consumption in the first 24-hours at a higher altitude is optimal

Descending – Descending to a lower altitude is probably the best thing to do if symptoms develop. Attempts to treat or stabilize the patient in situ at altitude is dangerous, unless highly controlled and with good medical facilities. People with moderate symptoms usually respond well if they descent just 1,000 feet (300 meters) and stay there for 24 hours. If the individual with moderate symptoms remains at this lower altitude for a couple of days their body will have become acclimatized and they can then start ascending again. People with severe symptoms should descend at least 2,000 feet (600 meters) as soon as possible. If this is not done quickly there is a risk of serious of life-threatening complications. People whose symptoms do not improve after descending 600 meters should go down further until they start feeling better. 

• Acclimatization – the best way to prevent altitude sickness is to ascend gradually, so that your body can become acclimatized to the changing altitude.
• Fluids – Consume between 4 to 6 liters of water per day.Take ORS. Avoid Caffine.
• Food – Eat a high calorie diet while at high altitude, esp carbohydrates.
• Exertion – Avoid Over Exertion.
• Stay Warm
• Sleeping – Avoid sleeping at high Altitudes and during the day. When your altitude is over 3,000 meters, ascend no more than 300 meters each night. On your route to Leh, we recommended you staying first night at Keylong (3,000m)  after Manali ( 2000m) and second at Sarchu ( 4290M). However Sarchu being at such an altitude, is the place where many people may suffer AMS.
• Smoking – Do not smoke or use tobacco or any other Drugs'
• Alcohol – Do not consume alcoholic drinks.
• Moderate symptoms – People with moderate symptoms should stay at their current altitude until their symptoms have gone completely.
• Medications – Acetazolamide / Dexamethasone medications can also be used to prevent altitude sickness. Some medications may make symptoms worse while at high altitude, or ascending, including tranquilizers and sleeping pills.

​According to the National Health Service (NHS), UK:

• Mountain sickness is fairly common among skiers, mountaineers and people who spend time at high altitudes.
• At a height of over 3,000 meters (10,000 feet) about three-quarters of people will experience mild symptoms.

In the UK altitude sickness does not exist. Ben Nevis, Scotland, UK's highest mountain is 1,344 meters (4,406 feet) high. No matter how fast you went up that mountain, you would not get altitude sickness. 

The average human body needs from 1 to 3 days to get acclimatized to a change in altitude. People who do not spend enough time acclimatizing to a new altitude before going further up have the highest risk of developing altitude sickness.  

There is a Very Usefull Book you can download from Here. Its your ultimate guide for travelling at high Altitudes. 

THATS WHY WE ALWAYS SUGGEST PEOPLE TO TAKE 3 DAYS WHEN THEY ARE DRIVING UP TO LEH SO THAT THEIR BODY ACCLIMATIZE TO HIGH ALTITUDES.