Background: Informal carers play an important role in the care of patients with mental illness. Little is known of the relationship experience of the patient and their informal carer (caring dyad) as the context for the intersection between physical and mental health. Aim: This study aimed to explore the impact of comorbid cardiometabolic risk (CMR), metabolic syndrome (MetS) and related diseases and severe mental illness (SMI) on the caring dyad.