This study explores the lived experiences of junior high school students in learning mathematics, particularly focusing on the transformation from mathematics anxiety to understanding. Mathematics anxiety is widely recognized as a significant factor affecting students’ cognitive performance and emotional well-being. However, limited research has examined how students experience and interpret this anxiety in their learning process. This study aims to describe how mathematics anxiety is experienced, constructed, and transformed into understanding from a phenomenological perspective. This research employed a qualitative approach with a descriptive phenomenological design. Ten eighth-grade students were purposively selected based on varying levels of mathematics anxiety. Data were collected through in-depth semi-structured interviews and analyzed using transcendental phenomenological methods, including epoche, horizontalization, and synthesis of meaning. The findings reveal that students’ learning experiences evolve through four essential themes: initial construction of anxiety, cognitive disruption, coping strategies and meaning negotiation, and transformation toward understanding. Mathematics anxiety emerges as an emotional and social experience that interferes with cognitive processes but can be reconstructed through supportive learning environments and adaptive strategies. This study highlights that mathematics learning is not solely a cognitive process, but also an emotional journey. The transformation from anxiety to understanding demonstrates the importance of integrating affective and cognitive dimensions in teaching practices. These findings provide implications for developing more humanistic and responsive mathematics instruction.