What is the cause of headache when traveling to Tibet? It is also accompanied by rapid heartbeat and difficulty breathing.

At high altitude, people who don't adapt will have some reactions because the air is thin.

Hypoxia is generally manifested as dizziness, headache, tinnitus, dizziness and weakness of limbs, followed by nausea and vomiting, shallow and weak breathing, and fast and weak heartbeat.

If it's not serious, get used to it.

If not, you can consider going back to a place with low altitude and abundant oxygen, or see if the pharmacy sells related drugs. There seems to be a kind of rhodiola that can cure hypoxia. Also, consider buying an oxygen bag.