It's often called the kissing disease -- mono -- and it's easily spread among teens. But it almost killed one student athlete.
Doctors didn't think this Gilbert boy would survive. His family was left clinging to hope after he slipped into a coma. All from mono, something most parents dismiss as a minor sickness -- but not in this case.
What went wrong?
Cody Middleton spent his first full day at home Wednesday with his mom, three brothers and friends. He was in the hospital for over a month.
He was in a coma for two weeks and when he woke up, he had to re-learn how to stand, walk and even speak.
Here's home video of Cody Middleton taking his first steps as a teenager.
The 15-year-old is walking for the first time on his own after a common virus nearly took his life.
"It felt weird. Just a month ago, I was running, playing football, then couldn't even stand up."
He caught mononucleosis, which is commonly spread among teenagers. But usually symptoms include feeling tired and sleepiness.
"Every day mono however, this went straight into his central nervous system and it happened like that," says Shelli Middleton, Cody's mom.
That led to brain swelling and paralysis. Then the high school sophomore slipped into a coma.
"I remember looking at the doctor saying, why isn't he waking up?"
Cody could no longer breathe on his own.
"For me, that was the worst day of my life. The worst moment of my life," says Shelli Middleton.
Mom Shelli says Cody stayed like this for a grueling two weeks.
"I would stand right next to his bed, I would hold his hands and stare at his hands and talk to him the whole time."
Finally, Cody responded to his mom's touch.
"It was the slightest squeeze from his hand, it was biggest continued piece of hope for me."
Cody is Gilbert High School's JV quarterback, and a passionate Green Bay Packers fan. Today, he sits at the kitchen table and tells jokes to his buddies.
Amazing to watch -- because doctors thought he'd never open his eyes again.
"I don't remember waking up, first thing I remember is saying mom."
A couple days after he caught mono he suddenly lost control of his body and his hands became tingly. Shelli took her son to the hospital. Even when Cody opened his eyes, the road to recovery was challenging. He was unable to talk.
"It was terrible, I had to find ways to get you guys to know what I was talking about," says Cody.
"We knew he could blink so we used that as a means of communication," says Shelli.
Physical therapists helped teach Cody how to stand and eventually walk. Doctors say Cody's recovery is nothing short of a miracle.
"I love you, sorry to put you through all that," Cody told his mother.
Cody is number 12 on the Gilbert JV team and he is trying to learn how to run again. By next year, the quarterback and safety hopes to be back on the team.