What is the average chance of getting delirium if I have advanced cancer?
Delirium is a sudden, serious change in mental function that causes confusion, trouble focusing, and altered awareness. It is common in people with advanced cancer. A large review of studies found that, on average, about 36% of patients with advanced cancer experience delirium. This number can vary based on how delirium is measured, but it gives a general idea of the risk.
What the research says
A 2025 systematic review and meta-analysis pooled data from 17 studies involving 9,007 patients with advanced cancer 1. The overall rate of delirium was 35.6% (95% confidence interval: 27.2% to 44.1%) 1. This means that, on average, about 1 in 3 people with advanced cancer will develop delirium. The review also found that the reported rate varied depending on which tool was used to assess delirium 1. Other sources in this set do not directly address delirium prevalence, but they cover related symptoms and treatments in advanced cancer, such as dyspnea 3, pain 6, and symptom management 2478.
What to ask your doctor
- What are the early signs of delirium I should watch for?
- Which factors might increase my personal risk of delirium?
- How is delirium diagnosed and treated in advanced cancer?
- Are there steps I can take to help prevent delirium?
This question is drawn from common patient questions about Oncology and answered using cited medical research. We do not provide individualized advice.