Chronic illness in a family member can cause emotional distress throughout the family, and may impair the family's ability to support the patient. This may cause a situational crises for the family and is important to know how to manage the distress it may cause.
Read the article review by The Journal of the Royal Society of Medicines about the impact of chronic diseases it has on the quality of life of carers, cargivers and patients. In further, they examine research on partner quality of life and higlight some of the methodological challenges and the clinical implications
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1282240/