There are several times when you may be in an altered state of consciousness. The mind, in other words, is altered. The term was coined and has been used to describe various ways of the mental state. It would depend upon the person you are talking to. Therefore, to define this term would really be impossible. However, society has seemed to confirm certain examples of people who are in altered states of consciousness.
Medications can alter the mind that is not normal. However, it depends on the person because not all drugs do that to people. This would be one way. Another way would be trauma, epilepsy, sleep deprivation, fasting, and psychosis. Sometimes, drinking alcohol can make you drunk and alter your state of consciousness.