The article discusses the importance of understanding illness trajectories in palliative care, particularly for patients with life-threatening illnesses and their caregivers. It highlights that when patients inquire about their prognosis, they are often seeking information not only about life expectancy but also about the likely patterns of decline. The authors review three main illness trajectories: a steady progression with a clear terminal phase (commonly seen in cancer), gradual decline with occasional acute deteriorations (seen in conditions like heart failure and chronic obstructive pulmonary disease), and prolonged gradual decline (typical of frail elderly or people with dementia). Each trajectory has distinct characteristics and requires different models of care. Understanding these trajectories can help clinicians plan and deliver more integrated and appropriate care, empowering patients and caregivers to cope with their situation. The article also emphasizes the need for advance planning and the importance of considering the patient's preferred place of care. Finally, it suggests that the insights gained from understanding these trajectories can inform better service planning and development, ensuring that resources are allocated effectively to meet the needs of patients with serious chronic illnesses.The article discusses the importance of understanding illness trajectories in palliative care, particularly for patients with life-threatening illnesses and their caregivers. It highlights that when patients inquire about their prognosis, they are often seeking information not only about life expectancy but also about the likely patterns of decline. The authors review three main illness trajectories: a steady progression with a clear terminal phase (commonly seen in cancer), gradual decline with occasional acute deteriorations (seen in conditions like heart failure and chronic obstructive pulmonary disease), and prolonged gradual decline (typical of frail elderly or people with dementia). Each trajectory has distinct characteristics and requires different models of care. Understanding these trajectories can help clinicians plan and deliver more integrated and appropriate care, empowering patients and caregivers to cope with their situation. The article also emphasizes the need for advance planning and the importance of considering the patient's preferred place of care. Finally, it suggests that the insights gained from understanding these trajectories can inform better service planning and development, ensuring that resources are allocated effectively to meet the needs of patients with serious chronic illnesses.