Physio-Cognitive Decline Syndrome (PCDS) is a clinical characterized by concurrent declines in physical and cognitive functions that precede disability. Taiwan's rapidly aging population highlights declines in physical and cognitive functions as precursors to disability, posing key challenges in geriatric care. Research shows these declines begin in early middle age and progress with age. Understanding middle-aged and older adults' experiences and coping strategies for Physio-Cognitive Decline Syndrome (PCDS) is essential for developing effective interventions. This study explored the subjective experiences and perceptions of PCDS among middle-aged and older adults to identify key themes and coping strategies in response to such declines. This qualitative study utilized purposive sampling, semi-structured face-to-face interviews with middle-aged (55-64 years) and older (≥65 years) adults to explore PCDS perceptions. Data were analyzed using content analysis. Participant experiences and perceptions formed three themes: (1) aging accelerates PCDS progression, (2) PCDS threatening daily life, and (3) adapting to changes. These findings further delineate a four-phase PCDS process: Individual Perception (recognizing decline), Life Threat (impact on daily life), Adaptation (accepting reality), and Positive Coping (implementing management strategies). Correspondingly, participants developed coping strategies to mitigate physical and cognitive decline, seek professional assessment, and strengthen support systems. Middle-aged and older adults with PCDS face physical and cognitive declines, mobility limitations, psychological stress, and social isolation. They adopt coping strategies like health maintenance, cognitive training, and social participation. Family and social support systems play a crucial role in their coping processes, while seeking professional medical assistance and engaging in community activities further enhance their confidence in managing PCDS.