On Sunday your mom was fine, chatting about her garden. By Tuesday she didn't know what day it was, insisted strangers were in the house and dozed off mid-sentence. You wonder whether this is dementia finally showing itself. More often, a change this fast is something else: delirium, a sign that something in her body needs attention now.
This guide uses MedlinePlus from the National Library of Medicine. It's general information, not medical advice. If your parent's thinking changes suddenly, contact their health care provider right away, and call 911 if they have trouble breathing, chest pain, sudden weakness on one side, slurred speech, or can't be woken.
What delirium is
Delirium is sudden, severe confusion caused by rapid changes in brain function that can happen with physical or mental illness2. A person with delirium is confused and disoriented and can't think or remember clearly. It usually starts suddenly and is often temporary and treatable1. Doctors may also call it an acute confusional state2.
There are three types1:
- Hyperactive. Restless, agitated, sometimes seeing or hearing things that aren't there.
- Hypoactive. Sleepy, slow, quiet or seeming depressed. This type is easy to miss.
- Mixed. Switching back and forth between the two.
Families often notice the hypoactive type last, because a parent who is quiet and sleepy doesn't seem to be in crisis. But a sudden drop in alertness can be just as serious. See elderly sleeping a lot. Medicines are a common trigger; see polypharmacy in the elderly.
Signs to watch for
Symptoms usually start over a few hours or a few days, and they often come and go1. Common signs include12:
- Changes in alertness. Often more alert in the morning and worse at night.
- Confusion about time or place. Not knowing the day, or where they are.
- Disorganized thinking. Talking in a way that doesn't make sense.
- Trouble paying attention. Losing track mid-conversation.
- Short-term memory problems. Forgetting what was just said.
- Hallucinations or false beliefs. Seeing people or things that aren't there.
- Emotional changes. Anger, agitation, irritability, depression or being unusually excited.
- Sleep changes. Drowsy in the day, awake at night.
- New incontinence. Accidents that weren't happening before.
The key clue is change. Compare your parent to how they were last week, not to how an average older adult acts.
Common causes
Many problems can trigger delirium. MedlinePlus lists common causes including12:
- Infections. Urinary tract infections, pneumonia and the flu. See UTIs in the elderly and pneumonia in the elderly.
- Dehydration and electrolyte problems. See dehydration in the elderly.
- Medicines. Side effects of sedatives, opioids, anticholinergic drugs and other pain medicines, or withdrawal after stopping a medicine.
- Surgery and anesthesia. Including reactions to anesthesia.
- Hospital stays. Especially in intensive care.
- Severe pain or lack of sleep. Both strain the brain.
- Alcohol or drug intoxication or withdrawal. Including after stopping drinking.
- Organ failure and serious illness. Including kidney or liver failure and advanced cancer.
Often more than one factor is involved, such as a mild infection, a new pain pill and a poor night's sleep in an unfamiliar hospital room.
Who is most at risk
Older age is a risk factor on its own. Others include having dementia, being in a hospital or nursing home, having surgery, having a serious illness or more than one illness, having an infection, and taking medicines that affect the mind or high doses of pain medicines1.
A parent with dementia is especially vulnerable, and delirium can be harder to spot because some confusion is already there. Watch for a sudden worsening over hours or days. That's different from the slow change of dementia. See sundowning, which can look similar but follows a daily pattern.
Delirium vs. dementia
Delirium and dementia can occur together, and acute problems that cause delirium may happen alongside the long-term disorders that cause dementia2. But they differ in important ways.
- Onset. Delirium comes on over hours or days1. Dementia develops over months or years.
- Course. Delirium often fluctuates during the day1. Dementia changes slowly.
- Attention. Trouble focusing is a hallmark of delirium.
- Reversibility. Delirium is often temporary and treatable1. Most dementias are progressive.
Never assume a sudden change is just the dementia getting worse. Get it checked. For the early signs of dementia itself, see early signs of dementia.
What to do right away
- Call the doctor the same day. A rapid change in mental status calls for a provider2. After hours, use the on-call line or urgent care.
- Call 911 for emergency signs. Trouble breathing, chest pain, sudden weakness or numbness, slurred speech, a high fever with stiffness, or if your parent can't be woken.
- Bring the medication list. Include over-the-counter drugs and supplements, and note anything new or recently changed.
- Describe the change clearly. When it started, what's different, whether it comes and goes, and what's normal for your parent.
- Note recent events. A fall, a new medicine, a fever, less drinking, constipation or trouble urinating.
- Stay with your parent. Confusion raises the risk of falls and wandering.
Your description matters. Providers who don't know your parent may assume confusion is their baseline. Say plainly: "This is not how my mother usually is."
How doctors find the cause
Diagnosis starts with a history of the symptoms and physical, neurological and mental status exams1. Depending on the situation, tests can include blood and urine tests, a chest X-ray, brain imaging such as a CT or MRI scan, and sometimes an EEG or spinal tap2.
Treatment focuses on controlling or reversing the cause, which can mean treating an infection, correcting dehydration, or stopping or changing medicines that worsen confusion or are no longer needed2. Some people need a short hospital stay. Medicines to calm severe agitation may be used, usually starting at very low doses2.
How families can help
Families play a big part in recovery, especially in the hospital. MedlinePlus notes that hearing aids and glasses may help, along with reality orientation and adjusting the environment, such as lighting to show day and night, clocks and calendars2. Practical steps:
- Bring glasses, hearing aids and dentures. Sensory loss adds to confusion2. See hearing loss in the elderly.
- Orient gently. Mention the day, the place and why they're there, without arguing.
- Keep day and night clear. Open the blinds in the morning; dim lights and reduce noise at night2.
- Bring familiar things. Photos, a favorite blanket, a familiar voice.
- Encourage drinking and eating. If the care team allows it.
- Help them move. Sitting up and walking with help, when the team says it's safe.
- Ask about every new medicine. Sedatives and some pain medicines can worsen delirium1.
Arrange for familiar people to visit in shifts if you can, especially in the evening when confusion is often worse1.
Recovery and what comes next
Delirium often lasts about a week, and it may take several weeks for thinking to return to normal. Full recovery is usually expected but depends on the cause2. Some people lose some ability to care for themselves for a time2, so a parent may need extra help at home after a hospital stay.
Before discharge, ask what caused the delirium, which medicines changed, and what signs should prompt a call. See hospital discharge planning. If thinking hasn't returned to normal after several weeks, ask the doctor about a follow-up cognitive evaluation.
If your parent lives in senior living
Being in a nursing home is a risk factor for delirium1, and residents of assisted living face many of the same triggers: infections, new medicines and dehydration. Ask the community how staff watch for sudden changes in thinking and how quickly they contact the doctor and the family. Make sure the care plan lists your parent's normal level of alertness and memory, so staff can recognize a change.
If you notice something first on a visit, tell the nurse on duty right away and ask that the doctor be called. Follow up the same day. See care plan meetings for how to raise concerns formally.
Questions to ask the care team
- What do you think is causing the confusion? Treatment depends on the cause2.
- Which tests are being done? Blood and urine tests are common first steps2.
- Have any medicines been added or changed? Medicines are a common trigger1.
- Can any medicines be stopped or lowered? Stopping unneeded drugs may help2.
- What can we do to help at the bedside? Orientation and familiar faces help2.
- How will we know it's getting better? Ask what improvement should look like and when.
Write down the answers and share them with siblings and other caregivers, so everyone gets the same information and nobody has to repeat the same questions.
An example
Eleanor, 84, became confused and sleepy over two days and started talking to her late husband. Her son called her doctor, who sent her for urine and blood tests. She had a urinary tract infection and was dehydrated1. With antibiotics, fluids and a pause in a new sleeping pill, she was back to herself in about a week2. This is an illustration; every case is different.
Lowering the risk
Treating the conditions that cause delirium lowers the risk. In the hospital, avoiding sedatives or using low doses, treating infections and metabolic problems promptly, and orientation programs reduce delirium in people at high risk2. At home, families can help by keeping an up-to-date medication list, encouraging fluids, keeping a regular sleep routine, and making sure glasses and hearing aids are used.
If your parent is having planned surgery, ask the surgical team about delirium risk and how they help prevent it, and plan for a family member to be there when your parent wakes up.
Getting help
Start with your parent's primary care provider. If caring for a parent through illness and recovery is wearing you down, see caregiver burnout and respite care.
