Altitude (meters above sea level)	Percentage of those Affected
3,000	40%
3,700	57.3%
3,900	63.8%
4,520	89.24% -
5,300	100%

The rates of acute altitude sickness 3,000 m, 3,700 m, 3,900 m, 4,520 m and 5,300m above sea level are 40 percent, 57.3 percent, 63.8 percent, 89.24 percent and 100 percent, according to a survey Although these values are typical, experts point out that the human body is very adaptable and has a magical capability for acclimation.
As breakthroughs have been made in determining the cause of altitude sickness and in the treatment, the cure rate of the two most common forms of acute altitude sickness -- high altitude pulmonary edema (HAPE) and high altitude cerebral edema (HACE) -- has reached 99%. 

Altitude sickness, also known as Acute Mountain Sickness (AMS), is a pathological effect of high altitude on humans, caused by acute exposure to low air pressure (usually outdoors at high altitudes). It usually occurs around 3,000 meters above sea level. Cold temperatures, high fever and extreme fatigue can all lead to altitude sickness.

Symptoms generally associated with mild to moderate altitude illness include:

·         Difficulty sleeping

·         Dizziness or light-headedness

·         Fatigue

·         Headache

·         Loss of appetite

·         Nausea or vomiting

·         Rapid pulse (heart rate)

·         Shortness of breath with exertion

 

Symptoms generally associated with more severe altitude illness include:

·         Bluish discoloration of the skin (cyanosis)

·         Chest tightness or congestion

·         Confusion

·         Cough

·         Coughing up blood

·         Decreased consciousness or withdrawal from social interaction

·         Gray or pale complexion

·         Inability to walk in a straight line, or to walk at all

·         Shortness of breath at rest

To prevent the occurrence of altitude sickness, visitors should have a proper rest and avoid strenuous activities days before you go to Tibet. After getting off the plane, you should try not to carry heavy things or run and avoid outdoor activities.

Nifedipinum, Nuodikang Capsules and Suoluomabao Capsules (known as Hongjingtian Capsules in Chinese) may help some people prevent the occurrence of altitude sickness when they are taken three days before arrival to a highland. Note: Acetazolamide (Diamox) is a drug used to stimulate breathing and reduce mild symptoms of mountain sickness. This drug can cause increased urination, so when taking this medication, make sure you drink plenty of fluids and do not drink alcohol; if you don’t drink enough water, it may result in serious dehydration, which can worsen AMS.

Visitors with a severe cold, a high fever, acute or chronic pulmonary diseases, severe cardiovascular diseases, women with an advanced pregnancy and children under three years of age should avoid traveling to regions with a high altitude

AMS is very common for most tourists when they first arrive on the high plateau. It can affect individuals differently based on their own health situation.

All of our itineraries are designed with altitude sickness in mind. We suggest our clients drink plenty of water, especially for the first few days, and do as little physical exertion as possible upon arrival. Most people need 2 to 3 days to acclimatize in Lhasa.