Circadian Rhythm Disorders
The human body functions according to a circadian rhythm thought to be controlled by a biological clock located in the part of the brain called the hypothalamus. There are several distinct disorders of our circadian rhythm and these are listed below:

1. Jet Lag
2. Shift Work related circadian disorder
3. Delayed Sleep Phase Syndrome
4. Advanced Sleep Phase Syndrome
5. Irregular Sleep-Wake Cycle