Many teenagers today do not get enough sleep, and this can lead to problems with emotions and thinking. This study looked at which daily behaviors might increase emotional problems in high school students who don’t sleep enough. A total of 81 students from Southern Thailand answered a survey about their phone use before bed, how well they manage their time, how often they exercise, and how they feel emotionally. The results showed that students who used their phones before bedtime were more likely to have emotional problems (OR = 7.34, p = 0.013). The biggest risk came from poor time management (OR = 21.46, p < 0.001). Not getting enough exercise also raised the risk slightly, but it was not a strong link (OR = 2.32, p = 0.214). The study found that when students had more than one risk behavior, their chances of having emotional problems went up even more. These results show that small, everyday habits—like staying on the phone too late or not planning your time—can have a big impact on emotional health. Helping students build better habits early may prevent emotional struggles later.