People always think the most when they are sleepy and asleep.

Because the brain doesn't have to work at this time. When I am free, I will think about things and reminisce.

All kinds of human activities need to consume energy, just like we need to eat for work and study, only when there is rest, there will be work to maintain strong energy, is the way for the body to function normally, sleepy so that the body can get rest, and it is also the best time for the brain to synthesize protein, especially in deep sleep, because the synthesis of protein can enhance memory, geographic enhancement work efficiency is really high, imagine if a person is not sleepy, the brain oxygen supply is insufficient, protein synthesis is insufficient, then the degree of forgetfulness will be greatly increased, and the efficiency will be significantly reduced, so work or study tired to be sleepy, when energetic to work hardIn fact, to put it in layman's terms, it is the same as when we are hungry to eat, and we have to work when we are full.

Because of the lack of oxygen, you will be sleepy.

The desire to sleep every day may be due to anemia or depression.

Generally, adult male hemoglobin 130g l is diagnosed with anemia, adult female hemoglobin 120g l is diagnosed with anemia, pregnant woman hemoglobin 110g l is diagnosed with anemia, children 6 years old hemoglobin 110g l is diagnosed with anemia, children 6-14 years old hemoglobin 120g l are diagnosed with anemia. Patients with anemia may have fatigue and weakness, want to sleep every day, and will also have symptoms such as shortness of breath and lazy speech, if it is more serious, there will be paleness, rapid heartbeat, etc., patients can be carried out according to the specific reason**, for example, if it is iron deficiency anemia, patients can follow the doctor's instructions to use ferrous succinate tablets, ferrous sulfate tablets, etc.

Patients with depression may also want to sleep every day, and will also show that they do not like to communicate with others, have a strong sense of self-blame and self-guilt, and severe patients will also have self-harm and suicidal tendencies.

People will feel that sleepiness is an alarm from the body's regulation, a response to the decay of bodily functions.

The scientific explanation is:

The lack of oxygen in the blood of the brain leads to a decrease in the excitability of brain nerve cells, and the person's attention is not easy to concentrate, so it appears unresponsive and susceptible to fatigue.

The most common belief is that sleep is to eliminate physical fatigue and make up for the exhaustion of a day's work.

The evidence for the "recovery" view is that during the first few hours of sleep, the pituitary gland at the base of the brain releases large amounts of growth hormone, which promotes the metabolism of proteins in the body, which promotes the growth and repair of tissues in the body.

Dr. Peter Garrick of the London Clinical Nutrition and Metabolism Research Group is negative. He believes that the biggest impact on protein metabolism in the body is diet.

Tissue bending increases when eating, and decreases when fasting. The main reason why protein metabolism changes at night is not sleep itself, but that people don't eat at night.

The core feature of sleep behavior is "sleep homeostasis" – as the duration of waking time increases, drowsiness gradually increases, eventually leading to sleep, and sleep is the process by which sleepiness is gradually cleared.

Current research suggests that drowsiness is related to the accumulation of a molecule called adenosine. Adenosine is a metabolite of the body's energy currency "ATP".

All life activities need energy to maintain, and maintaining a state of wakefulness will balance the dispersion and continuous consumption of a large amount of ATP. The longer you are awake, the more ATP is consumed, and the more adenosine molecules, the "metabolic waste" of ATP, accumulate.

The more adenosine molecules accumulate outside the cell, the more obvious their inhibitory effect on neural activity, and the more sleepy the person becomes.

The caffeine in coffee, which we are familiar with as a life-sustaining artifact, can hinder adenosine molecules from binding to adenosine receptors, and play an antagonistic role in antagonizing adenosine's inhibition of neurons, thereby maintaining wakefulness.