Dangers & Annoyances
If you’ve acclimatised for a few days in Lhasa, the gradual rate of gain along the southern route to Kailash shouldn’t pose any serious problems, though the jump from Lhatse (3950m) to Raka (4925m) or Saga (4610m) involves a potentially dangerous rise in elevation. An overnight at Sakya (4280m) or Rongphu Monastery (4980m) en route will help your body adjust.
If you’re coming from Nepal you should be particularly careful as you won’t be well acclimatised; an overnight in Kyirong (2800m) or Dzongkhar (4135m) and Drongba (4570m) won't give you enough time to acclimatise unless you've been trekking in Nepal beforehand. Better tours fly to Lhasa for a few days first and then head out to western Tibet via Gyantse, Shigatse and Lhatse.