The four states of consciousness are waking consciousness, sleep/dreams, hypnosis, and drugs. Waking consciousness: is the mental state that encompasses the thoughts, feelings and perceptions that occur when we are awake and reasonably alert. An example of waking consciousness is doing your daily activities such as driving, taking care of children, or even schoolwork.   Sleep/dream: everyone needs sleep. You have an internal alarm clock called suprachiasmatic nucleus (SCN) that tells you when to wake up, and when to go to sleep. There are four stages of sleep. Stage one: Light sleep averaging 10 minutes where brain waves are active and indicate the early stages of sleep. Stage two: Lasts approximately 20 minutes. Stage three and four: Deep sleep, averaging 30-40 minutes in each stage. There are also sleep disorders such as insomnia, sleep apnea, and narcolepsy. Hypnosis is a psychological state with physiological attributes superficially resembling sleep and marked by an individual's level of awareness other than the ordinary conscious state. Psychoactive drugs are a chemical substance that crosses the blood-brain barrier and acts primarily upon the central nervous system where it affects brain function, resulting in alterations in perception, mood, consciousness, and behavior.   The four states of consciousness to me are that you may not always aware of what is going on with reality in different states. Only when you are awake, are you fully aware of what is going on around you. You can become so sleep deprived that it can affect your ability to focus and define what is real and what is not. I have realized that the sleep I am getting is not enough, especially since it is very rare that I fall into a deep sleep.