Pressure points are one of the most misunderstood and exaggerated areas of MA.
Kyusho is the Japanese word.
PSNA stands for Pressure Sensitive Nerve Areas, an American anacronysm.
People who don't know about them claim there are anywhere between 25 and 360 and they do various things. You can buy lists and charts showing all kinds of alleged PSNA. Most of these do nothing. The ones that do something are meaningless unless you are shown how to apply them in combat in real tme.
For example, we punch to the chin for a KO. A groin kick will stop an attacker. But to actually land these shots you need to train for them, not just know them theoretically. So it is with PSNA.
I teach a primary list of 54 PSNA for use in combat.
(One for each week of the year more or less!)
I do not give out lists and charts to be memorised. You learn these PSNA in context, in the dojo, and you remember them.
There are 3 kinds of PSNA:
ones you strike
ones you press
ones you rub