Informal care is a substantial source of support for people with cancer. However, various studies have predicted its disappearance in the near future. The aim of this study is to analyse the catastrophic effect resulting from the substitution of informal care with formal care in patients with blood cancer throughout the different stages of treatment. A total of 139 haematological neoplasm patients who underwent stem cell transplantation in Spain, completed a longitudinal questionnaire according to the three phases of treatment between 2012 and 2013.