The internal carotid artery runs up the front-side of your neck, just under where a collar sits — right where a well-placed collar choke sits too.
What actually tears
A tear in the inner lining creates a second channel — a false lumen, where blood was never meant to flow. That false channel causes trouble two ways: it can bulge inward and narrow the real channel, reducing blood flow to the brain, and the raw, injured surface can form clots that break off and travel on into the brain — a stroke.
Where a pseudoaneurysm comes in
Sometimes the outer wall balloons outward at the injury site, forming a pseudoaneurysm — a bulge contained by the outer layers rather than a full, normal artery wall. Many are followed with repeat imaging rather than treated aggressively. That can change if an aneurysm is expanding, or if symptoms keep returning despite treatment.
How it’s usually found
Diagnosis generally involves imaging of the neck vessels — commonly CT angiography or MR angiography. The delay between injury and diagnosis is one of the things this site’s registry tracks, because “it was dismissed as a muscle strain” is a recurring theme in survivor accounts.
How grappling loads this artery
The internal carotid is relatively fixed where it enters the skull base and relatively mobile in the neck. In the published case reports from martial arts, injuries to this artery cluster toward that upper, distal end. Why they cluster there is not established — it is tempting to assume the fixed-to-mobile transition explains it, but no study has shown that, and measured neck movement produces far less strain than it takes to tear a healthy artery. The positions below are ones that load the neck, which is not the same as showing they cause harm:
- Collar chokesCross collar, bow and arrow, loop choke: direct, sustained pressure over the artery’s path.
- Guillotines and arm-in variationsCompression plus neck flexion and often a twist.
- Kesa gatame and head-and-arm pressureSustained lateral load on the side of the neck.
- Stack passes and can openersExtreme flexion, sometimes with rotation, under an opponent’s weight.
Naming these positions is not saying they are unsafe or should be banned. Chokes are applied millions of times a year worldwide, and the overwhelming majority of them injure nobody. It is saying that if a dissection occurs, this is the kind of loading that shows up in the story.