Tracy James broke the scary news Saturday, saying RD was having a number of tests done in the hospital to confirm what exactly had happened to him ... this after returning home from work Thursday night and feeling terrible from what she says was a likely heart attack.

She writes, "He has had test run and we’re currently waiting for the results.he has also seen a kidney specialist and will have a stress test done. He’s always been on bp meds for high bp. Just please pray all the test come back for something we can fix."

Tracy goes on to say she's a wreck, but trying to stay positive ... leaving it in God's hands to get her hubby back home safely. She also sent out a somewhat reassuring update.

Sounds like Road Dogg's kidneys are all clear, and a cardiac catheterization is scheduled for Monday to decide the next steps.

Road Dogg's perhaps most famous as part of the D-Generation X tag team collective from WWF's Attitude Era, which was also made up of guys like Triple H, Shawn Michaels, Rick Rude, Chyna and others ... including RD's partner in crime in the ring, Billy Gunn, who helped make up one half of the New Age Outlaws with Road Dogg.

Road Dogg wrestled professionally in WWF/WWE until the early 2000s, at which point he went off and competed in other leagues until about 2011 ... never coming back into the WWE fold officially ... until he re-signed as a producer and a writer for them, that is.

He's reported as being behind the scenes for several 'WrestleMania' events and the head writer for other WWE shows, including 'SmackDown' and others. And, yes, Road Dogg is a Hall of Fame member too ... having been inducted as part of the Class of 2019.