Quick answer
What could sudden confusion mean?
Sudden confusion, also called delirium, is a rapid change in awareness, thinking or behaviour. It can be caused by infection, stroke, low blood sugar, medicines, seizures or other serious illness. Call 999 or attend A&E because the cause needs urgent assessment.
Recognising delirium
The person may be disorientated, unable to focus, hallucinating, unusually drowsy, agitated or behaving unlike themselves. The change can come and go.
While waiting for help
Stay with them, remove immediate hazards and speak calmly. Do not give food or drink if swallowing is unsafe. Bring a medicine list and describe when the change began.
Why assessment is urgent
Treatable causes can worsen quickly. Tests may include blood glucose, oxygen level, infection checks, an ECG or brain imaging depending on symptoms.
Common questions about sudden confusion
- How can I check whether someone is confused?
- Ask their name, age, where they are and today's date. New difficulty answering needs urgent help, but normal answers do not exclude serious illness.
- Is sudden confusion the same as dementia?
- No. Dementia usually progresses gradually; delirium develops over hours or days and often fluctuates. A person with dementia can also develop delirium.
- What can cause sudden confusion?
- Causes include infections, stroke, low blood sugar, medicines, seizures, head injury, alcohol withdrawal and heart or lung problems.