Most treks in Tibet are rather strenuous and occur at elevations between 3660m to 5200m. People with diabetes, asthma, or high blood pressure can successfully trek in Tibet, but should check with a doctor about potential problems and precautions. A medical examination report signed by a physician as a pre-condition is required for treks in Tibet.
It is also advisable to have a dental checkup before you set off. Except for street "dentists" in the markets, with foot-treadle drills, the only dental facility in Central Tibet is in Lhasa and Shigartse.
It is important to carry a basic first-aid kit with you. Few drugs familiar in the West are available in China and Tibet. Be familiar with the proper use and potential side effects of the drugs. Some of these medications can only be purchased with a prescription, which most doctors will provide if they know you are going trekking. If you plan to travel through Nepal, you can purchase many of the antibiotics and pain killers cheaply in Kathmandu without a prescription. The suggested quantities of medicines and materials are based on the needs of one person during a two to four weeks visit in Tibet. Check with your doctor on appropriate dosage.