Purpose <p>Differentiated thyroid cancer (DTC) is a type of cancer with a favorable prognosis, but the physical and mental well-being of patients following surgery, particularly during the initial treatment period, is often overlooked. Gaining insight into patient experiences during this phase can offer valuable information for developing programs aimed at promoting health-related behaviors among patients. This study aimed to explore the experience of patients with differentiated thyroid cancer from the perspectives of healthcare providers and patients using symptom management theory (SMT).</p> Methods <p>Semi-structured interviews were conducted with DTC patients and healthcare personnel. Interviews were audio-recorded, transcribed verbatim and analyzed using content analysis and Colaizzi analysis. The NVivo 20 software was used.</p> Results <p>The following five themes and associated categories were identified: (1) dual nature of psychological symptoms; (2) perception of somatic symptoms; (3) the relationship and impact of psychological and physical symptoms; (4) active management attempts; and (5) realistic barriers to symptom management.</p> Conclusions <p>This study reveals that DTC patients face complex and fluctuating physical and mental symptoms during the initial treatment phase. These symptoms interact with each other and significantly reduce the patients’ quality of life. Although some patients attempt to cope actively, common barriers such as insufficient awareness of symptoms, unscientific management methods, and passive coping result in poor symptom management outcomes. There is an urgent need to establish a systematic symptom management support system.</p>