C-Knight — an original member of rap group The Dove Shack — is fighting for his life, with his loved ones waiting on some key tests before any next steps … TMZ has learned.

The MC’s father, George Lee Washington Blount Jr., tells us his son was hospitalized on Oct. 18 as a result of a scary blood sugar level — which we’re told stems from his diabetes. Blount says that while C-Knight was receiving dialysis, he somehow suffered a stroke.

In addition to that, we’re told C-Knight went into cardiac arrest … and that his heart stopped, with him needing to be resuscitated by doctors. At that point, Blount says C-Knight was placed on life support — but Blount says even more health issues surfaced amid all this.

Since the stroke and cardiac arrest … we’re told C-Knight has been in an unresponsive state, and that the medical staff has told the family there’s no signs of progress they’re detecting.

As for where things stand now … Blount tells us they’re waiting on a crucial MRI scan to be done, which will tell if them if there’s any notable brain activity. We’re told the family believes he can battle back and recover from this … despite how grim it looks at the moment.

In the case that the scan shows no brain activity — which is the worst case scenario — we’re told his family plans to keep him on life support for the time being … and will weigh their options. For the time being, they’re praying for a miracle, hopeful he can pull through.

The Dove Shack only released 2 albums, but they’re both memorable … especially for their impact on the West Coast G-Funk movement in the ’90s, which was spearheaded by Snoop Dogg and Warren G — both of whom are familiar with these guys, and friendly with them.

The other members, 2Scoops and Bo-Roc, are obviously tight with C-Knight — and Bo called for everyone to send their thoughts and well-wishes his way as CK tries to bounce back.