Reigns, a four-time world champion, took the decision because of his ongoing battle with leukaemia.
The wrestler revealed he was diagnosed with leukaemia when he was just 22 years old and he had been in remission.
“When I was 22 years old, I was diagnosed with this. And very quickly I was able to put it in remission. But I’m not going to lie, that was the hardest time in my life,” Reigns told WWE’s Monday Night Raw.
“My real name is Joe and I have been living with leukaemia for 11 years,” Reigns added.
“Unfortunately, it is back and because the leukaemia is back I cannot fulfil my role, I can’t be that fighting champion and I’m going to have to relinquish the Universal Championship.”
Reigns, who leads a 3-man wrestling group, known as The Shield, added before dropping his belt that he was not retiring.
Before leaving the ring, Reigns assured that he will be back to wrestling soon.
“I want to make one thing clear — by no means is this a retirement speech,” Reigns said.
“I will beat this and I will be back, so you will see me very very soon.”