The high altitude and people's reaction to it is one of the difficulties to travel to Tibet. But it is not as serious as you imagine especially when you know it and get prepared for it.
 Do exercises to keep you fit before coming to Tibet.
- Avoid catching a cold.
- Make sure you have a good sleep the night before you flying to Lhasa.
- You'd better not to take any activities for the first day in Tibet.
- After getting off your airplane in the airport or walking out of the railway station, try to walk slowly, take some deep breath. 
Make sure you are familiar with your tour routes in Tibet and read some guidebooks and introductory material concerning Tibet to enrich your knowledge of the scenic spots, culture, customs, art and religion in the region.
• Avoid doing too much before the journey. Tourists should try to be in optimal health if traveling to Tibet, so they do not want to catch a cold, be taking medicine or suffering from hypertension or heart diseases.
Take common-use medicines with you on your trip, especially cold and diarrhea medicines. Sunglasses and sun-block creams are also necessary for the trip because of the strong sunlight on the plateau.
When in Tibet
 After arriving in Tibet, tourists usually should take a good rest - for at least half a day. They are also advised to avoid unnecessary exertion.
Please do not consider altitude sickness a big deal. Westerners usually show fewer symptoms than Chinese, while women are typically also strongly affected than men.
The Potala Palace sells a quota of 1,000 admissions every day and tourists who want to visit the palace have to go there one day ahead to collect a coupon allowing them to buy a ticket the following day. The visitors' quota applies only to the Potala Palace.
Young Tibetans and Tibetan Lamas are generally comfortable speaking English, so it is not a big problem for foreigners to communicate with them.