The 27-year-old, who's now a drummer in a band, tweeted about his health scare Tuesday morning, writing, "I was in the hospital last Friday. I suffered a 'Mini Stroke', which was not fun at all."
Muniz told ABC News he was riding his motorcycle last Friday in Phoenix, Arizona when he suddenly lost his vision in one eye and his body became numb, reported Radar Online.
"I couldn't say words. I thought I was saying them, and my fiancee was looking at me like I was speaking a foreign language," he said.
The actor says he thought he had a bad headache, but after undergoing tests at a hospital, doctors discovered he suffered a mini-stroke.
"I've literally to this day never had a sip of alcohol in my life. I've never had any drugs. I've never even smoked a cigarette," he added.
Munis says he still plans to play drums for his band Kingsfoil on tour next week and marry his fiancee next year.