Article in English: Sadness is a normal reaction to many life events and ongoing situations. You may feel sad when you experience loss, when your feelings get hurt, or when things don't go your way. Understanding the source of your sadness can help you begin to process the feeling and deal with it in a healthy way. Here are some common reasons people experience sadness:  Loss of a friendship or another close relationship Death of a loved one, or separation from a loved one  Bullying Low  self-esteem  Hearing about a tragedy Being sad doesn't feel good, so it's tempting to try to push the feeling away instead of taking a closer look. However, identifying the feeling of sadness will help you isolate it from your other emotions. Looking sadness square in the face will help you notice when the feeling starts and ends, making it easier to handle.  You might experience sadness as a physical sensation. Maybe your arms and legs feel heavy or you have an uncomfortable feeling in the pit of your stomach. You might feel lethargic, too. It can help to picture sadness as an image. You've probably heard people describe feeling a "wave of sadness." Try picturing sadness in your own way. It could be a towering wave or a deep, dark pool. If you're not sure what it is, it might help to draw a picture of how sadness makes you feel. Recognize when sadness comes, and allow yourself to accept the feeling instead of pushing it away. If it's a wave, let it wash over you without resisting. Think about what's making you sad and realize that your feelings are valid.  A normal bout of sadness can last just a few minutes or much longer, depending on the reason why you're sad. As you process the sadness, recognize when it comes to a natural end. Pay attention to when you feel a little lighter, and you're able to turn your attention to a new emotion. Next time you feel sadness, recognize that it's an emotion that will come and go, just like other emotions. It can help to have a plan for what you'll do during and after the bout of sadness, so you know this is...

Summary in Vietnamese:
Phản ánh lý do khiến bạn buồn. Chú ý cảm giác và thời điểm bạn thấy buồn. Học cách chấp nhận cảm giác và điều khiển nó. Lên sẵn kế hoạch khi bị nỗi buồn tấn công. Tìm kiếm dấu hiệu trầm cảm.