The objective of this study was to highlight the heterogeneous nature of the medical profiles of patients living in long term care units (LCU) and to present the morbidity factors associated with-the weight and burden of ensuring long term medical care and treatment. Typology analysis, performed on a group of 600 LCU patients, highlights two types of patients: one who is characterised by having few or no serious diseases, and the other (representing nearly one-third of the sample population) corresponding to patients with serious poly-pathologies and requiring a high level of medical attention and nursing care. Factors associated with a higher level of care are diseases such as those related to cardiac or respiratory deficiencies. This predictive model for the burden of care could be used to measure the suitability between the state of the patients and the their optimum structures for care.