An altered state of consciousness (ASC), also called altered state of mind or mind alteration, is any condition which is significantly different from a normal waking state. – Wikipedia
Different from a normal waking state means almost any state is considered altered. And, if our normal waking state is mid to high beta brain wave then normal is a state of stress! In our current societies that state has become normal.
It is, however, very easy to flip out of beta...