If you do not alternate labor activity with rest, then fatigue can take a chronic character and go into overwork, which is more difficult to cope with. This may require a long rest or even treatment.
The first signs of schoolchildren fatigue: decreased academic performance, loss of appetite, tearfulness, irritability, sleep disturbance.
The causes of overwork are, as a rule, improper organization of work, excessive training load, ignoring the hygiene requirements of the daily regimen.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.