Mwepu featured in each of the Seagulls' opening six Premier League games this season before he was taken ill whilst on a flight to join up with Zambia for last month's international break.
After a spell in hospital in Mali, the midfielder returned to Brighton to undergo further cardiac tests which have concluded that his illness is due to a hereditary cardiac condition.
With Mwepu at risk of suffering a cardiac arrest should he continue playing, he has now been advised to end his football career for his own safety.
An statement from Mwepu read: "A boy from a small Zambian township called Chambishi has some news to share.
"He stood strong to follow his dream of playing football at the highest level, and by the grace of God he lived his dream by reaching the Premier League.
"Some dreams, however, come to an end so it is with sadness that I announce the need to hang up my boots because of the medical advice I have received. This is, however, not the end of my involvement with football. I plan to stay involved in some capacity.
"I would like to take this opportunity to thank everyone that supported me in my football journey, including my wife and family, my agent 12MAN, the Zambian FA, all my previous clubs, team-mates and coaches and especially everyone at Brighton & Hove Albion."
Brighton chairman Tony Bloom said, "We are all absolutely devastated for Enock. He and his family have had a traumatic few weeks and while we are just thankful he has come through that period, he has seen such a promising career cut short at such a young age.
"As a club we will give him all the love, help and support we possibly can to make a full recovery, and then as he decides on the next steps in his life."
Head coach Roberto De Zerbi added, "I am so sorry for Enock. Before I arrived I looked at all the squad, and he was a player I was so excited and looking forward to working with. We will do everything we can to help him."
Mwepu began his professional career in his native Zambia with Kafue Celtic FC before moving to Europe to join Austrian champions Red Bull Salzburg in 2017.
After a spell on loan with Austrian second-tier outfit Liefering, Mwepu then established himself as a first-team regular with Salzburg and went on to record 18 goals and 20 assists in 119 appearances across all competitions before moving to Brighton for around £20m in July 2021.
Mwepu struggled with a hamstring injury for large spells of last season with Graham Potter's side, but he still managed to play 21 times in all tournaments, scoring two Premier League goals in games against Liverpool and Arsenal.
The 24-cap Zambia international ends his career at Brighton with three goals and seven assists to his name after 27 appearances, and the Seagulls currently sit seventh in the Premier League table, two points behind the top four.