Signal one: It is difficult to make decision. In order to plan a vacation, you stay up to determine the specific dates and the specific locations, but in the next day, you still hesitate in some details such as the seat on airplane is on the left or right, call a taxi right now or wait for a moment. Expert studying on sleep from University of California said that when people felt exhaustion on both physical and mental, they can’t identify important information and irrelevant information. As a result, the simplest decision is magnified. Moreover, fatigue people are more easily took a gamble and finally made the wrong decision.
Signal two: Always feel hunger even had eaten a lot. Studies have shown that lack of sleep for a long time would disrupt blood sugar levels, causing the body produce less leptin and more ghrelin. The former is a hormone which suppresses appetite while the latter is a hormone that stimulates appetite. These physiological changes will inevitably lead to overeating. The spokesman of American Academy of Sleep Medicine said fatigue people are particularly love sweet foods and other simple carbohydrates, which can quickly fill their stomachs. In addition, the lack of sleep reduces self-control ability.
Signal three: Have cold constantly. People who lack of sleep are more susceptible to disease. In a study, the healthy respondents are injected flu virus by researchers. The results showed that people who have less than seven hours sleep time are more likely to be infected with influenza virus. As for people who have only four hours of sleep every night for several consecutive days, their immune response to influenza vaccine inoculation is weaker.
Signal four: Always want to cry. Yes, lack of sleep causes emotional volatility. One study found that people more easily depressed if they lack of sleep, because the exhausted brain will put aside more negative memory. Sleep deprived people’s behavior is very similar with depression patients.
Signal five: the ability to reflect is slow in thought or action. Researchers on Human Sleep Research Center from Stanford University said that the vast amount of evidences showed sleep deprived people’s ability to reflect is slow. In addition, Sleepiness can lead to impairment of balance and depth perception.