There are several possible reasons for feeling weak and sleepy: 1. Cold, due to viral infection invading the body can make people feel weak, sore, sleepy and sleepy. It is possible to check the blood count and C-reactive protein to determine whether there is a viral infection. 2, leukopenia, leukopenia can also cause weakness, reluctance to move performance. 3, poor sleep quality, may be caused by excessive dreaming, too light sleep, insufficient sleep time, stay up late, etc. 4, obstructive sleep apnea syndrome, due to obesity combined with rhinitis or tonsillitis, etc., causing airway obstruction during sleep This leads to lack of oxygen in the body, which is manifested as sleepiness, lack of concentration and weakness the next day. 5, anemia, mainly weakness, when the anemia is serious, sleepiness and difficulty in breathing can occur. 6, hypothyroidism, due to the lack of thyroid hormone, the body’s low metabolic state, causing weakness, reluctance to move, sleepiness and other performance.