The specific causes of sleepiness and lack of energy are as follows: 1. To find out whether there are problems with sleep habits, some people do not get enough sleep at night or sleep at irregular hours. 2. Some people have sleep disorders, such as respiratory arrest sometimes during sleep, sleep apnea can also cause sleepiness and lack of energy during the day. 3. Some episodes of sleeping sickness are very easy to get sleepy and sleepy during the day, sometimes suddenly falling asleep during normal activities. 4.If it is difficult to fall asleep or even wake up early, it can also cause serious insomnia, making the day sleepy and lack of energy. 5.Some people have certain diseases, such as hypothyroidism, the body is not able to produce a sufficient amount of thyroid hormone, thyroid hormone and the body’s energy storage and utilization are closely related, hypothyroidism can cause sleepiness and lack of energy. 6.Some people have long-term sadness, depression, affecting daily work and Depression, affecting daily work and life, serious depression, making patients sleepy, no spirit. 7, sleep among some adverse effects, such as serious noise at night, or their own body of certain diseases, such as restless legs syndrome, or night cramps, can cause sleep affected. 8, some people work special, often night shift work, changing time zones, or some special drugs, can also cause daytime sleepiness and lack of energy.