: "So when I went back to the doctor there was some stuff I never even knew.
"They give you those certain words: "Hey man, you got sleep apnea. Sleep apnea can cause hypertension or strokes, you could die."
"I said, "What?" "You could die." So now I've got to sleep with a sleep machine.
"I had to really get checked out. When they hit you with that three-letter word that starts with D and ends with E, it changes stuff up."
Sleep apnea is when a person's breathing stops and starts while they are sleeping.
Milder symptoms can include gasping noises, loud snoring and waking up a lot during the night.
'YOU COULD DIE'
Shaq's condition appears serious enough to require a CPAP machine, which will involve him wearing an oxygen mask as he sleeps.
He was also warned to cut down on his use of painkillers, which were starting to affect his kidneys.
Shaq continued: "[The Doctor said] 'All those painkillers you were taking, bro? Your kidneys are kind of weak. No more painkillers.'
"I was dependent upon painkillers - not addicted.
"Certain days when I couldn't move, I just popped one or two, just to get me going. But I'm off that now."
Despite his health worries, the 15-time NBA All-Star is determined to stay in shape with a regimented exercise and food plan.
And after bringing up his half-century birthday earlier this month, O'Neal is no longer trying to push his body beyond the limit.
He continued: "[My workouts are] just cardio - 30-40 minutes - then chest, arms, biceps, triceps.
"A simple old man workout. I can't do all that CrossFit stuff.
"[I try to eat] a healthy breakfast—fruit and fruit and fruit—then chicken and fish. I eat a healthy breakfast just to hold me for the day.
"The problem is when I'm on the road and I can't get to that.
"I'm a creature of habit - I love sandwiches, I love wraps, I love burgers.
"With the full discipline to where I'm not doing that, I'm gonna have the body of a 19-year-old."
O'Neal spent the majority of his NBA career with the LA Lakers, winning the MVP award in 2000 and finally hanging up his boots in 2011.