What is upset about means?

Native speaker’s answer
Rebecca
'Upset about' is a phrase that typically indicates a feeling of emotional distress or dissatisfaction caused by a particular situation or event. When someone is upset about something, they may feel sad, frustrated, angry, or disappointed. For example, if a person's favorite sports team loses an important game, they may feel upset about the outcome. Similarly, if someone receives negative feedback at work, they may be upset about the criticism. Overall, 'upset about' is a way to express a negative emotional reaction to a particular situation or circumstance.