EXCLUSIVE

Suge Knight had way more than a panic attack after court Tuesday ... he was having an intense physical reaction to a potentially fatal blood clot ... TMZ has learned.

TMZ broke the story ... Suge began experiencing chest pains after he was taken from the holding area at the courthouse to the hospital. Suge family sources tell us, doctors determined he's suffering from yet another blood clot -- like the one that almost killed him in a Vegas jail 3 months ago.

We're told the clots began forming after Suge was shot 6 times last summer at 1OAK during VMA weekend.

Our sources say Suge has now been moved to Long Beach Memorial where doctors have put him on blood thinners ... but it's clearly a serious situation.