Tolerance

What is Tolerance?

Tolerance means that after continued drinking, consumption of a constant amount of alcohol produces a lesser effect or increasing amounts of alcohol are necessary to produce the same effect.

Humans develop tolerance when their brain functions adapt to compensate for the disruption caused by alcohol. "Chronic heavy drinkers display functional tolerance when they show few obvious signs of intoxication even at high blood alcohol concentrations (BAC's), which in others would be incapacitating or even fatal"(Chesher & Greeley, 1992).

What's the Difference?

Imagine two people with different levels of tolerance, but the exact same BAC level. How are they different?

The person with high tolerance might show:

  • Better short term memory
  • Ability to hold a conversation
  • Ability to keep eye contact
  • Less intensified moods
  • Better speech, less slurring of words

But some things don't improve with tolerance. Both people will have:

  • Impaired eye-hand coordination
  • Impaired balance
  • Impaired motor function
  • Decreased peripheral vision

Notice anything? The things that don't improve with tolerance are pretty important for things like driving a car! That's why the legal BAC limit to drive is a set number, and does not depend on whether or not the person has a high tolerance. 

Problems Resulting from High Tolerance

  • Physical damage and impairment are occurring without your knowledge.  With tolerance, you feel less drunk, so you’re less able to accurately judge your ability to function.
  • Your body no longer protects you the way it is meant to – since you’re less likely to vomit or pass out, you may reach even higher, more toxic BAC levels.
  • When you develop tolerance, you can no longer experience the “buzz” – you don’t get the same euphoric effects at low doses.
  • It’s expensive – since you don’t feel the effects as quickly, you end up buying more drinks.
  • Tolerance and withdrawal are the two things that distinguish alcohol abuse from alcohol dependence – if you’re building your tolerance, you’re moving toward physical addiction.