The issue of intensive and palliative care in patients with chronic disease frequently arises. This review aims to describe the prognostic factors of chronic respiratory diseases in stable and in acute situations in order to improve the management of these complex situations. The various laws on patients' rights provide a legal framework and define the concept of unreasonable obstinacy. For patients with chronic obstructive pulmonary disease, the most robust decision factors are good knowledge of the respiratory disease, the comorbidities, the history of previous exacerbations and patient preferences. In the case of idiopathic pulmonary fibrosis, it is necessary to know if there is a prospect of transplantation and to assess the reversibility of the respiratory distress. In the case of amyotrophic lateral sclerosis, treatment decisions depend on the presence of advance directives about the use of intubation and tracheostomy. For lung cancer patients, general condition, cancer history and the tumor treatment plan are important factors. A multidisciplinary discussion that takes into account the patient's medical history, wishes and the current state of knowledge permits the taking of a coherent decision.