Definition of Failure to Thrive in Adults
Failure to thrive in adults is a clinical syndrome characterized by insufficient weight gain or weight loss, decreased appetite, poor nutrition, and functional decline, typically occurring in the context of multiple concurrent chronic diseases and impairments. 1
Core Clinical Features
The syndrome manifests through several key components that distinguish it from normal aging:
- Weight loss and nutritional decline that progresses beyond expected age-related changes 2, 3
- Decreased appetite with poor nutritional intake 1, 3
- Functional impairment including decline in activities of daily living and self-care abilities 2, 4
- Inactivity and social withdrawal with loss of interest in social activities 3, 4
- Progressive decline in physical and/or cognitive function that is insidious and gradual 4, 5
Distinguishing Characteristics from Normal Aging
The deterioration in failure to thrive exceeds what would be expected from normal, age-associated decline. 6 This is a critical distinction—the syndrome represents pathologic decline rather than physiologic aging 5.
Four Prevalent Syndromes
Four specific syndromes are repeatedly identified as both prevalent and predictive of adverse outcomes in adults with failure to thrive 2, 3:
- Impaired physical functioning with decreased ability to perform daily activities 2, 3
- Malnutrition with progressive weight loss and nutritional deficiencies 2, 3
- Depression contributing to decreased appetite and social withdrawal 2, 3
- Cognitive impairment affecting self-care and decision-making 2, 3
These four syndromes interact with and influence each other, creating a complex clinical picture where each syndrome may simultaneously contribute to the others 2.
Clinical Context
Failure to thrive typically occurs in the setting of multiple concurrent chronic diseases and functional impairments rather than as an isolated condition. 1, 2 The syndrome has been recognized with its own ICD-9 code since 1979, though this conceptual framework can create barriers by reinforcing fatalism rather than prompting systematic evaluation of reversible causes 2.
Important Clinical Caveat
The term "failure to thrive" describes a state of decline that is multifactorial, not a specific diagnosis 3, 5. Using this label should prompt comprehensive evaluation of the four key syndromes and their underlying causes rather than serving as a terminal diagnosis. 2, 3 The diagnosis represents a critical decision point that should trigger discussion of treatment goals and end-of-life care options 3.
Differential from Pediatric Definition
While the term was exported from pediatrics in the 1970s, the adult definition differs substantially 2. In adults, the syndrome encompasses chronic concurrent diseases and functional impairments rather than primarily growth failure, and it carries implications for end-of-life planning that are unique to geriatric medicine 2, 3.