Your travel insurance should at minimum protect you against trip cancellation and trip interruption; this can be useful should you need to cancel your trip due to circumstances such as sickness, emergencies or training injury.
Your Insurance should also cover high altitude trekking (do not confuse this with mountaineering or mountain climbing which is not covered by most insurance providers) and medical evacuation and repatriation costs. If you reside in the USA, we recommend Travel Guard and If you reside outside the USA we recommend World Nomads.