Cameron Menzies required medical attention after falling ill during his World Matchplay second round match against Ross Smith in Blackpool on Wednesday.
Leading the game 2-1, Scotland’s Menzies walked away from the oche and appeared unsteady on his feet as Smith and the England referee escorted him safely from the stage.
It was later confirmed that Menzies was cleared by medics backstage, but was unable to return to the stage to continue and therefore lost the match.
The PDC said: “Cameron had high blood pressure which caused him to feel dizzy and then lose consciousness.
“Following an assessment by the on-site medical team, Cameron was deemed healthy enough to return to his accommodation.
“We wish Cameron all the best and look forward to his soon return to action.”
Elsewhere, seventh seed Gerwyn Price knocked out former world champion Ross Cross with a dominant finish.
With the score tied at 2-3, the Welshman won six legs in a row to take control of the match before winning 11-5 to set up a quarter-final match with Smith.
World number three Jan van Veen booked his place in the quarter-finals by beating Dutchman Wessel Neumann in a tiebreaker.
The contest saw both players score over 100 to extend the match, but in the thriller it was Van Veen who came out on top 14-12.
Sixth seed James Wade completed the Matchplay last eight with a comfortable win over compatriot Ryan Searle, seeded 11th.
Wade, who won the competition in 2007, will face Van Veen in his 14th Matchplay quarter-final after winning 11-8.