WWE star Daniel Bryan has been forced into retirement after suffering a series of concussions.

The 34-year-old announced the news on this week's episode of Monday Night Raw.

“I took a test that said my brain wasn't as OK as I thought it was,” Bryan said.

“So it is with a heavy heart and the utmost sadness that I officially announce my retirement."

Bryan suffered three concussions in just the first five months of his 16 year career.

“When I woke up this morning, I felt nothing but gratitude, because I have gotten to do what I loved for 16 years,” he said.