Purpose: Family caregivers are important to facilitating the rehabilitation of individuals with brain injury. However, research shows spousal carers often reporting poorer health and well-being with psychosocial challenges including increased marital dissatisfaction. This study explores the accounts of participants caring for a spouse with brain injury. Materials and methods: This study used semi-structured interviewing and interpretative phenomenological analysis. Results: One theme, “Living in and beyond the loop of fear”, with two subheadings is reported. Participants’ attempts to manage their fears prominently defined their early caregiving. Fears were aggravated by the vulnerability of their spouse’s health which partially owed to brain injury sometimes having no symptoms prior to its onset. Consequently, participants anxiously strove to prevent further harm to their spouse’s health due to what they perceived as the continued “hidden” threat of brain injury. Therefore, participants became hypervigilant, leaving themselves vulnerable to burnout. Over time, some participants modified care practices and managed fears using beliefs accepting their limits to protect their spouses’ health. Conclusions: Findings suggest that beliefs conducive to acceptance helped carers to develop more sustainable, less over-protective, care. Interventions to help carers develop similar beliefs could be provided in therapeutic settings. Recommendations for future research are made. Implications for Rehabilitation: Caring for a long-term partner with acquired brain injury has considerable challenges which can threaten an individual’s health and well-being. Our research reports on carers’ experiences of anxiety which they managed through hypervigilant and overprotective practices which put them at risk of burnout. Consequently, we recommend the promotion of care beliefs that reframe caregiving: recognising the carer’s limitations to safeguard a spouse, whilst accepting the vulnerability of the spouse’s health. We propose that promoting such principles in therapeutic settings may better equip carers emotionally to provide sustainable care, something which could benefit the carer and spouse’s rehabilitation alike.