This study is a multi-method, two-city, intensive, in-depth qualitative study of Huntington's disease (HD) caregivers (HDCs) in Colombia. I explored the Colombia HDCs' experience through the Hispanic culture of caring. I develop the theory of the subrogate agency based on 5 functional stages of HD from Shoulson and Fanh (1979). This study was conducted in two different regions of Colombia, Medellin and Juan de Acosta, in which high rates of HD cases have been identified. The data were collected through three methods: (a) 56 interviews with HDCs and 8 with physicians; (b) 28 participant observations of Huntington's disease sufferers (HDSs); (c) 4 interviews and 8 focus groups of 6 members each with HDCs of late HDSs. Human agency is the ability to monitor one's own action. This study showed that the gradual and serious loss of all capabilities in HDSs has a social effect on the HDSs' agency. HDSs' survival depends on the subrogation that the HDC offers to the HDS. The HDS retains self-hood, i.e. agency, through the HDC's action. This subrogation causes a paradoxical consequence, resulting in both negative and positive effects on the caregiver. The theory of surrogate agency is supported by the data. Through the progressive phases, the capacity of the sufferer for expressing suffering, and social embarrassment, as well as the capacity to fight against the illness and provide reciprocity to their caregivers, deceases. The reason is that physical and cognitive impairments, as well as depression and anger, continue to increase. The study also documented important socio-cultural differences among the study regions. For instance, HDC's solidarity was based on blood and friendship; in larger cities, HD fragmented families. The study also found that HD is taking an immense toll on caregivers, sufferers and families because they are excluded from the Colombia's Basic Health Plan.