Among teenagers, some online topics or challenges may have a negative impact on mental health and even trigger the urge to self-harm. Although the specific popularity of these challenges will change over time, there are several types that require special vigilance: 1. **Dangerous challenges**: Some challenges require participants to try dangerous or risky behaviors, which may result in physical injury. For example, the previously popular "Fire Challenge" and "Tide Pod Challenge". 2. **Self-harm simulation challenges**: Some challenges may encourage participants to display or simulate self-harm behaviors, which may have a negative impact on those vulnerable teenagers. 3. **Diet and body challenges**: Some topics involve extreme diets, dieting, or harmful displays of body image, which may cause or aggravate eating disorders. 4. **Psychological manipulation games**: Such types as the "Blue Whale Challenge" allegedly encourage participants to cause self-harm after a series of increasingly dangerous tasks. When facing these challenges, it is very important to identify and monitor possible risks, provide appropriate psychological support and education, and cultivate teenagers' critical thinking skills and correct understanding of media content. If you find abnormal changes in teenagers' behavior or psychological state, it is key to seek professional help.