Mike Swick would awaken in the middle of the night, a searing pain across his chest. Had he not known better, had he not been in his 20s and exceptionally fit, he would have sworn he was having a heart attack.

Repeatedly, the attacks would come, putting him in agony and costing him precious sleep.

Even when the body is cooperating and everything is working as expected, the job of a professional fighter is an extraordinarily difficult one. When you're unable to sleep through the night, when you're feeling each morning as if you've survived a heart attack, it's almost impossible.

Swick's issues began in 2007, about the time he was preparing to fight Yushin Okami at UFC 69 in Houston. At first, it wasn't particularly bad, but as time went on, the intensity and frequency of the discomfort increased substantially.

He finally got to a point where he realized that his career as a professional fighter was very much in jeopardy.

"I never thought about wanting to quit myself," Swick said. "But I thought my career might be over, talking to the doctors."

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Doctors were mystified by Swick's condition. It was misdiagnosed several times, first as GERD (Gastroesophageal Reflux Disease) and, later, as dyspepsia, with a lot of other hypotheses offered, as well. He was given a slew of different medications and had Botox injected into his esophagus.

None of it helped.

"All this time, I'm trying to compete and be a professional athlete and it was just agonizing," Swick said. "I was going through all this training and not eating the right amount of foods, going to all these treatments, taking all these prescription medicines. It got to a point where I thought I was done. I had to figure out how to make this work, or my career was going to be over."

After all of that trial and error, and significant suffering along the way, Swick was diagnosed with esophageal spasm, a condition with no known cause and no surefire cure.

His discomfort peaked when he went to England to fight Dan Hardy at UFC 105 on Nov. 14, 2009. A win would have gotten him a shot at the welterweight title. He was, however, in no shape to win.

Throughout his training camp he felt miserable. He was having regular attacks in the night and would lose hours of sleep at a time. Given the extreme nature of his training regimen, quality sleep is essential and he wasn't getting nearly enough.

"That was when I was really getting scared and getting stressed out," Swick said.

He fought once more after a loss to Hardy, getting choked out by Paolo Thiago at UFC 109 on Feb. 6, 2010.

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He hasn't fought since because of the esophageal spasm as well as an alarming run of bad luck with injuries.

He'll return to the cage Aug. 4 when he meets DaMarques Johnson at UFC on Fox 4 at the Staples Center in Los Angeles, ending a period of 910 days on the sidelines.

"The funny thing is, when you go from being a full-time UFC fighter like me, who had 12 UFC fights, to being a full-time fan and not being able to fight and just watching UFC after UFC after UFC for 2½ years, it's frustrating," Swick said. "It's frustrating because you want to be out there fighting. The longer you go without fighting, the more forgotten you are and it seems the less you've done and accomplished."

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