Research about Chokes

Although, during training or in completion, it is near impossible to choke/strangle a person to death (used in Judo since 1882, no deaths have been attributed to their use), there are other ways the person may die. One way is bradycardia and arrhythmia based on carotid sinus stimulation, and the other way is positional asphyxia. The bradycardia way means that if you are pressing at just the right spot, very high and fairly lateral on the neck, up behind the sternocleidomastoid muscle, and only an inch lower than the jawbone, you may accidentally put your thumb on the sensor located in the wall of the carotid where it divides into internal and external branches. That sensor tells the heart to slow down if the blood pressure going into the brain is too high. If you push hard enough on the vessel and suddenly increase the pressure in it, the sensor tells the heart to slow down, and the heart obediently slows down to almost nothing, at which point it can start to fibrillate and you die.

The reason this is rare is dual. Number one, the sensor is small and difficult to reach, so it is chance if you happen to be over it. Number two, young people with resilient arteries are almost all resistant to this reaction to carotid compression. Older people with hardened arteries are much more susceptible. Positional asphyxia may happen when grappling. If you are pressing on the opponent's diaphragm with your body weight while applying a choke, then he or she will not be able to breathe. They will not be able to initiate a breath. If opponent is face down, it may also occur.