Your brain produces four primary types of brain waves: Beta, Alpha, Theta and Delta. Beta is primarily active during your awake state, which is the majority of your day. Alpha has to do with your subconscious, and is dominant during relaxed states when your eyes are closed but you are not asleep. Theta is present briefly during the periods before you fall asleep and before you fully wake up. Delta is primarily active when you are asleep. All of these brain waves are equally important to your health, and neurological disorders can be attributed to specific brain waves. For example, when you have brain irregularities caused by a head injury, your brain may have too much frontal theta or delta being produced when you are supposed to be awake and alert. By retraining these abnormal patterns in the affected areas, symptoms can be improved or eliminated.