Circadian cycle regulates the sleep and wake cycle of the person. This causes the physical, behavioral changes in a human being. It is responsible for showing the response a dark and light. Every night about 9 hours of sleep is necessary for maintaining the circadian cycle.
Here, the person had less sleep in the night so his circadian cycle will get disturbed, which caused him inflammation of body which develops as sores due to the production of inflammatory proteins. As a result he felt achy.