Many people have the habit of staying up late, some of them are helpless, due to the nature of their profession; others are voluntarily enjoy the night life, the night life as a sign of modern civilization. For the latter, it is simply on a road of no return. During the day the human organism has been working all day, if the night and then do not get proper rest, the body will certainly be burned out until the strike. There is a proverb that says: “eat a head of pig during the day, rather than a call at night”, its meaning is extremely profound. The medical profession is this evaluation of staying up late: before twelve o’clock is not sleep is “shameless”, before three o’clock in the morning is not sleep is “not life”. Then why is it not suitable for ordinary people to stay up late? This is decided by our brain and internal organs. Most of the activities of the healthy human body show a 24-hour circadian physiological rhythm, which is compatible with the 24-hour cycle formed by the regular rotation of the Earth, indicating that the human physiological rhythm is synchronized by the influence of periodic changes in the external environment (the intensity of light and temperature). Circadian rhythms exist in the human body such as body temperature, pulse, blood pressure, oxygen consumption, and hormone secretion levels. This clock-like biological structure in humans is called the “biological clock”. The central biological clock is located in the optic suprachiasmatic nucleus in the hypothalamus of the brain and is composed of more than 2,000 nerve cells that are directly regulated by light; the peripheral biological clock is located in metabolism-related organs, such as the liver, fat, muscle, heart and kidney, and is regulated by environmental factors (mainly light). The link between the central and peripheral biological clocks is mostly mediated by endocrine hormones, such as insulin and glucagon secreted by the pancreas, adiponectin and leptin secreted by the fat, and ghrelin secreted by the stomach, which regulate glucose metabolism. The production of these hormones has a circadian rhythm, usually high during the day and lower at night to ensure that the metabolism of food can be promoted during the day. If a person’s nighttime activities increase, such as night work, overtime, night eating, sleep disorders, etc., the body is affected by the circadian rhythm can not provide enough trample secretion hormones to participate in metabolism, then the excessive food intake at night will be stored because it can not be disposed of in a timely manner, which in the long run will lead to the body to produce a variety of fat and sugar metabolism-related diseases, such as obesity, diabetes and cardiovascular disease. If friends who stay up late often go to the clinic, they often get the following reply. Gastroenterology professional doctor told you: stay up late to cause indigestion stay up late when many people will eat late night snacks, late night snacks stagnant in the stomach for a long time, prompting a large amount of gastric juice secretion, gastric mucosa caused by stimulation, over time, easy to cause gastric mucosa erosion, ulcers. And at night the gastrointestinal tract does not get rest, dysfunction, constipation and other problems come. Oncologists remind you that staying up late increases the risk of cancer. Staying up late for a long time is a cause of high tumor incidence, because staying up late can lead to the disruption of endocrine hormone level, which makes the cell metabolism abnormal and affects the normal division of human cells, leading to cell mutation and increasing the risk of cancer. The International Agency for Research on Cancer has long determined that night shift is a strong cancer-causing factor. Compared with people who work from 9 to 5, the risk of late-stage tumors increases by 24% and the risk of early-stage tumors increases by 49% among night shift workers. Heart and neurological experts believe that: staying up late can induce cardiovascular disease because when staying up late, people are in a state of chronic stress and constantly secrete hormones such as adrenaline, which can cause abnormal vasoconstriction. Long-term lack of sleep makes people feel nervous and anxious, which can easily induce or aggravate hypertension. For patients who have atrial fibrillation, arrhythmia, coronary artery disease, etc., staying up late invariably adds load to the heart, which can easily lead to myocardial infarction and other accidents. Nephrologists directly warn you: staying up late hurts the kidney long-term stay up late, will not only cause increased blood pressure, proteinuria hematuria aggravated, the key is to make the residual kidney units are always in a high state of operation, increasing its workload and residual kidney pressure, accelerating glomerulosclerosis. In addition, the immunity of patients who stay up late for a long time is significantly reduced, inducing colds and other infections, which is often an important factor in the recurrence of kidney disease. Staying up late for a long time not only hurts the body, but also hurts the mind. Many patients who have the habit of staying up late have long-term combined sleep disorders and even neurasthenia and other problems. This is because the sympathetic nerves are generally resting at night and excited during the day, stay up late when the sympathetic nerves remain excited at night, and these symptoms will appear during the day. Staying up late for a long time may also increase the risk of depression. Therefore, for most people do not often stay up late, especially those who suffer from hypertension, diabetes, kidney disease and other chronic diseases or have a family history of corresponding diseases, must pay attention to the rhythm of the biological clock regular life, do not because of their own ignorance or impulse long-term wandering in staying up late such a “road to injury”.