Prince Harry required urgent medical attention during his gruelling trek to the South Pole last year (13) after suffering severe altitude sickness, exhaustion and dehydration.

The British royal joined actors Alexander Skarsgard and Dominic West and teams of wounded soldiers to tackle the challenge as part of the Walking With the Wounded charity mission, and they managed to reach the Antarctic on 13 December (14).

However, video footage shot for a U.K. TV documentary of the expedition reveals the 29 year old struggled through the trek and required help from doctors after his efforts left him in crippling pain.

In an upcoming episode of Harry's South Pole Heroes, which will air in the U.K. on Sunday (23Mar14), he admits, "Antarctica jumped up and bit me on the a**."

He later adds, "If you show a weakness to Antarctica, I think it exploits it. And I think it will slowly grind you down until you have the utmost respect for it, which I now have.

"I thought I could come out here and just crack on and see it through without any issues, make sure I'm here for the guys (fellow adventurers) when they need me.

"I'm frustrated and disappointed in myself, but it really does prove how physically and mentally tough these guys are."

The Walking With the Wounded teams faced a string of problems as they battled through the 200-mile (322-kilometre) trek after bad weather conditions delayed progress and threatened to derail the adventure on multiple occasions.