The reason for the lack of energy and special fatigue throughout the day may be caused by physiological factors, or may be caused by pathological factors. 1. Physiological. Excessive mental stress, lack of sleep:Excessive mental stress, such as heavy workload, learning pressure, etc., if coupled with poor sleep quality or resulting in insufficient sleep, can lead to fatigue and weakness. Excessive exercise:Excessive exercise can overdraw the body and lead to weakness. 2.Pathology. Depression:Typical manifestations of depression that is easy to fatigue, weakness, lack of concentration, sleepiness, memory loss and so on. Tumor, anemia, hypothyroidism: Tumor, anemia, hypothyroidism and other consumptive diseases, can consume nutrients, resulting in weakness, fatigue and so on. All day weakness excludes physiological factors, should consult a doctor in time to clarify the diagnosis.