Purpose: We examined the self-care experiences of adolescents with spinal muscle atrophy (SMA) and their perceptions of the interactions between their body and the environment. Methods: We interviewed ten adolescents with SMA aged 13–18 years regarding personal care practices. Purposive sampling was conducted in two medical centers in northern Taiwan. Data were analyzed using the Giorgi analysis method. Results: Four constitutions were identified: (1) limited space for independent development, (2) multiple reconstructions of self-image to improve physical ability, (3) self-care of disease, and (4) developing activity styles to accommodate social culture. Conclusion The self-care lived experiences of patients reflect dynamic changes in the body and environment. Self-existence was exhibited by adjustment, practice, and creativity of physical activity to integrate into society. Nursing staff should understand the self-care experiences and needs of adolescents with SMA to develop a database of self-care skills. This study recommended that nursing staff improve their ability to guide patients in taking care of themselves by developing body awareness self-care courses and individual care plans in response to various stages of disability to help patients delay deterioration, realize their physical potential, and promote independence and social development.