What Are The Most Severe Effects Of Drinking Liquor?

Death.
Or if you are "lucky", addiction and brain damage.

Ethanol, the alcohol we find in alcoholic drinks is in fact a poison. It is not a particularly strong poison but never the less it is a poison.  It makes the drinker intoxicated and light headed, both of which are pleasant feelings, and are the reasons most people drink.   But some people become addicted to it and can't live without a regular drink.  And usually quite a lot as well. They turn into a regular drunken bum. They drink rapidly to become drunk - a famous case was the fabulous soccer player George Best who appeared in a TV interview drunk.  But he was sober and hadn't had a drink when the interviewer left him in the studio's recreation room to start the show.  15 minutes later Best was introduced and was clearly drunk.  In just 15 minutes of rapid drinking!

Some stupid people have drinking competitions, to see who can drink the most, or to see who can drink a bottle of whisky or vodka the fastest.  Unfortunately, the amount of ethanol in a full bottle is just about enough to kill you.  And it regularly does.

The poison also kills brain cells and over a long period of time leads to brain damage.