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sundowning versus delirium

Key points

  • Sundowning is predictable—it happens at the same time each day, usually late afternoon/evening, and follows a pattern.
  • Delirium is sudden, can happen any time, and fluctuates unpredictably throughout the day.
  • Delirium is a medical emergency often caused by infection, dehydration, or medication issues—it needs a doctor.
  • Keep a simple journal of times and behaviors for 2-3 days to spot the pattern.
  • If the behavior is new, sudden, or at an unusual time, treat it as possible delirium and seek medical help.
  • Use calming environmental changes for sundowning; for delirium, focus on safety and getting medical attention.
  • Trust your gut—you know your loved one best. If something feels off, don't wait.

General caregiving information, not medical advice. Check medications and major care changes with your clinician.

Step-by-step

  1. 1. Check the clock first. Sundowning almost always starts in the late afternoon or early evening, around the same time each day. If the confusion began at 10 a.m. or 2 p.m., or if it's a completely new time for your loved one, suspect delirium.

  2. 2. Ask yourself: How fast did this start? Sundowning builds gradually over the afternoon. Delirium comes on suddenly—within hours or even minutes. If your loved one was fine at lunch and by 2 p.m. is wildly confused, that's a red flag for delirium.

  3. 3. Look for a pattern over 2-3 days. Keep a simple log: write down the time, what happened, and how long it lasted. Sundowning will show a consistent daily pattern. Delirium will be erratic—good hours and bad hours with no rhyme or reason.

  4. 4. Assess their attention. In sundowning, the person can usually be redirected and may still follow simple directions. In delirium, they often cannot focus at all—they may be easily distracted, stare into space, or seem 'out of it' even when you try to engage them.

  5. 5. Check for physical clues. Delirium is often caused by an underlying medical problem. Gently check for signs of infection: fever, pain when urinating, cough, or a change in skin color. Also consider if they missed a dose of medication, haven't drunk enough water, or are in pain from arthritis.

  6. 6. Try a calming intervention. If it's late afternoon and the behavior fits the usual sundowning pattern, try a known calming strategy: offer a warm drink, put on soft music, dim harsh overhead lights, or guide them to a simple hand activity like folding towels. If they calm down, it's likely sundowning. If they remain agitated or get worse, consider delirium.

  7. 7. Observe for 'hyper' or 'hypo' arousal. Delirium can make a person either very agitated (hyperactive) or very drowsy and hard to wake (hypoactive). Sundowning is usually more about agitation and restlessness. If your loved one is unusually sleepy, confused, and hard to rouse, that's a delirium warning sign.

  8. 8. Trust your gut. You know your loved one's usual patterns. If something feels 'off'—like they are not themselves in a way that doesn't match their typical sundowning—don't wait. Call their doctor or a nurse helpline and describe the sudden change.

  9. 9. When in doubt, seek medical evaluation. If you cannot confidently rule out delirium, especially if the change was sudden, the person has a fever, or they seem unusually drowsy, take them to an urgent care or emergency room. Tell the staff: 'My loved one has dementia and this is a sudden change from their normal behavior.'

What not to do

  • Do not assume it's 'just sundowning' if the behavior started at an unusual time. Many caregivers miss delirium because they think all confusion is dementia-related. Instead, always check the time of onset—if it's not the usual late afternoon, treat it as a potential medical issue.

  • Do not try to 'reason' or argue with a person in delirium. Their brain is not processing information normally, and arguing will only escalate fear and agitation. Instead, use a calm, reassuring tone and simple one-step directions like 'Let's sit down here.'

  • Do not ignore physical symptoms like fever, pain, or changes in urination. Delirium is often caused by infections that are treatable. If you notice your loved one wincing when they move, or if they have a strong-smelling urine, mention it to the doctor.

  • Do not change their routine drastically in an attempt to 'fix' sundowning. A sudden change in routine can actually trigger more confusion. Instead, make small, consistent adjustments like adding a calming activity at the same time each afternoon.

  • Do not skip the journal. Without a written record, it's easy to misremember patterns. A simple log of times and behaviors is the most powerful tool you have to distinguish sundowning from delirium—and to share with the doctor.

Practical tools

  • The 'Time & Behavior' Journal

    Keep a small notebook or use a notes app on your phone. For 3 days, write down: the time the behavior started, what it looked like (e.g., pacing, repeating questions, staring), how long it lasted, and what helped (or didn't). This pattern will reveal if it's predictable sundowning or erratic delirium. Share this log with the doctor during appointments.

  • The 'Red Flag' Checklist for Delirium

    Print or save this short list: (1) Did this start suddenly? (2) Is it happening at an unusual time of day? (3) Is the person unusually drowsy or hard to wake? (4) Do they have a fever, pain, or smell of infection? (5) Have they missed medications or fluids? If you answer 'yes' to any of these, call the doctor.

  • Calming Phrases for Sundowning (and What to Avoid in Delirium)

    For sundowning, use validating, gentle phrases: 'I see you're feeling worried. Let's sit together and look at this photo album.' Avoid asking 'why' questions. For delirium, keep it even simpler: 'You're safe. I'm here. Let's take a sip of water.' Do not ask them to explain themselves.

  • Environmental Adjustments for Sundowning Prevention

    In the late afternoon, close curtains to reduce glare and shadows that can be misinterpreted as threats. Turn on soft, warm lamps instead of harsh overhead lights. Play calming music or nature sounds. Offer a warm, non-caffeinated drink like chamomile tea. These steps can reduce the severity of sundowning and make it easier to tell if a sudden change is actually delirium.

  • The 'Three-Question' Test for Attention

    To quickly check attention, try: (1) 'Can you look at me for a moment?' (2) 'What did you have for lunch today?' (3) 'Can you squeeze my hand?' A person with sundowning may be able to respond, even if confused. A person with delirium may be unable to focus or follow even simple requests.

Discuss with your clinician

Ask your doctor: 'Given my loved one's type of dementia, what are the most common triggers for delirium that I should watch for?'

If your loved one has a history of sundowning, ask: 'At what point should I bring them to the ER versus calling your office first?'

Discuss any new medications or recent dose changes—these are common delirium triggers. Ask: 'Could this new medication be causing confusion?'

If your loved one has had delirium before, ask: 'What is the best way to manage future episodes at home, and when is hospitalization necessary?'

For people with Lewy body dementia, ask: 'How can we tell the difference between a normal fluctuation and a delirium episode that needs treatment?'

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