Staying up late seems to be commonplace for young people nowadays. We often hear people around us advising us: "Don't stay up late, go to bed early. Staying up late is very harmful to your health." So what exactly are the dangers of staying up late? And what time at night counts as staying up late?
What are the risks of frequent late nights?
We often hear about the dangers of staying up late, but what actual effects does it have on the body? Professor Chen Zuhui from the First Affiliated Hospital of Jinan University once stated in an interview that the human body maintains a delicate balance between yin and yang. When normal sleep patterns are disrupted, this yin-yang equilibrium becomes disturbed. Simply put, staying up late disrupts this balance.1. Increased risk of internal heat buildup
Frequent night owls know this well. The day after staying up late, some may experience hoarseness, sore throat, dry mouth, and other symptoms—all signs of internal heat. This occurs when yin energy becomes deficient and yang energy becomes excessive after sleepless nights.
2. Increased susceptibility to colds
After staying up late, the body experiences a rise in false heat while vital energy is depleted, lowering resistance. This makes the body vulnerable to external pathogenic factors, commonly leading to wind-cold invasion and colds.
3. Triggering Chronic Diseases
Persistent disruption of the day-night cycle throws the body's yin-yang balance off, paving the way for various chronic illnesses. While the immediate harm from staying up late may not be felt, the cumulative damage will manifest over time. Moreover, the adverse effects of sleep deprivation become increasingly pronounced with age.
4. Increases Cancer Risk
Staying up late disrupts the body's biological clock, raising the risk of cancer. As early as 2007, the World Health Organization classified staying up late as a Group 2A carcinogen.
What Time Counts as Staying Up Late?
Many define staying up late as going to bed past a certain hour at night, but this isn't the correct understanding.Staying up late refers to not sleeping during the late night hours, staying awake all night, or generally resisting sleep despite feeling drowsy late at night.
Whether you continue working into the night doing tasks typically done during the day, or rest during the day and focus on work at night—All these scenarios qualify as staying up late. Even if you go to bed early but only sleep for two or three hours—far below your required sleep duration—this still counts as staying up late.
So, if you sleep from 1 AM to 10 AM the next day, is that still staying up late? Theoretically, no—since you've secured sufficient sleep, it's merely going to bed late. However, this isn't advisable either, as it disrupts your sleep schedule.