The condition understandably took its toll on Jeffress, but now that he is being properly medicated, the symptoms have gone away and his daily routine is back to normal.
"The Blue Jays checked me into a hospital in Buffalo and they finally found out what was wrong," Jeffress said. "They have really good doctors there and they figured out I was on the wrong medication. The medication I was on wasn't a long-lasting overnight medication for me, it was for younger kids. They put me on extended-relief type of medicine that worked."
Jeffress began experiencing the symptoms back in 2008, but he never received a clear explanation about what the cause was. He lives in Arizona during the offseason and went for multiple examinations over the years where doctors would examine his sleeping patterns, but the prescribed medication didn't seem to help.
The only real piece of advice Jeffress received was to get more rest, but the symptoms were most prevalent in the morning, so every time Jeffress went to bed his anxiety level would rise. He never quite knew what the next day was going to bring.
It was a stressful time not only for Jeffress, but also for his family and teammates. In the Minor Leagues, players often share rooms on the road, so there was quite a number of people who witnessed the seizures and twitches, but everyone felt helpless because nothing could be done to help his condition.
"The anxiety part was probably one of the toughest things," Jeffress said. "Just waking up knowing that at any point a seizure, I can't even explain it, it just pops up on you.
"You could be doing the smallest thing like brushing your teeth and just ironing clothes or whatever and you just fall down. Just being around there, being by myself, I used to not be able to drive, so a lot of that stuff wears on you."
Jeffress was suspended multiple times in the Minor Leagues because of positive tests for marijuana. In hindsight, he may have been self-medicating in order to help deal with his illness.
Thankfully those issues now appear to be a thing of the past. Jeffress hasn't experienced any seizures in the past two months, and he can once again focus on making things right in his professional career.
That can only be a good thing, and there's still plenty of promise for the former No. 1 Draft pick of the Brewers. He recently touched 101 mph on the radar gun during a game in Arizona, and it's easy to see why he was once a key part of a trade between the Brewers and Royals that saw Zack Greinke go to Milwaukee.
Baseball is a results-oriented business that creates enough pressure on its own. Jeffress came to Spring Training this year knowing that all it would take was potentially one bad outing to cost him a spot on the big league roster. That pressure would be enough to mess with anybody's head, but when you add in the off-the-field issues, then it was almost too much to take.
Now that the anxiety is mostly gone in his personal life, Jeffress is better equipped to handle whatever happens in his career. It has been a long road, but finally there is plenty of hope for a long future in baseball.
"Just coming in here knowing I have to do a job and knowing it's going to be looked at very closely, it takes a lot of toll on you," Jeffress said. "To get that one side of your health life taken care of where you don't have to worry about getting enough sleep and stuff like that, it took a lot of pressure off."
The big question mark surrounding Jeffress' career has been his ability to throw strikes. He has walked 33 batters in just 40 2/3 Major League innings and in a lot of ways has been his own worst enemy on the mound.
That started to change toward the end of his Minor League season. He walked just one batter in his final 10 innings with the Bisons while striking out 14. The string of positive outings led to a September callup, and even though he might be uncertain about his future in the Blue Jays organization, the most important thing is that he's headed in the right direction.
Jeffress dropped his arm slot to more of a three-quarters angle, and the mechanical change combined with his improved mental state is cause for optimism. It remains to be seen how much of an opportunity he'll get before the end of the year in an overcrowded Blue Jays bullpen, but all the tools are there and it will be up to him to take it to the next level.
"Sometimes it takes longer to click for guys, but you still have to have some command," Blue Jays manager John Gibbons said. "At the big league level they lay off a lot of balls out of the zone. When you throw that hard guys get fooled, and when they get fooled they won't swing at it. So if it's not in the strike zone it will lead to walks.
"You hope you're the team that has those guys when everything clicks."