An altered state of consciousness, also called a non-ordinary state, dream state, or trance, can be any state that is generally different than a normal state of consciousness. There is no clearly defined boundary between “normal” and “altered” states of consciousness, but it’s generally understood that in an altered state, a person feels “awake” but in a manner different than a person normally experiences it. This state can be reflected physically—in how one senses one’s own body—and mentally—in how one is processing information. Though they are most commonly associated with the use of psychedelic drugs, altered states can sometimes purposefully be brought about by hypnosis, hallucination, or meditation or accidentally through witnessing or experiencing a traumatic event, undergoing a brain injury, or suffering from oxygen deprivation, among other triggers. Many report having religious, mystical, or spiritual experiences while in an altered state, though the experience is not always pleasant or enlightening. There is great interest in both the scientific and spiritual community in the interplay between consciousness and the physical body that occur during altered states.