Delirium is a sudden and severe change in a person’s mental state that causes confusion, disorientation, and difficulty thinking clearly. It often develops quickly—within hours or days—and can affect people of all ages, though it’s most common in older adults or those in the hospital. Delirium is a medical emergency and should be taken seriously.

What Is Delirium?

Delirium is a temporary but serious condition that affects the brain’s ability to function normally. People experiencing delirium may have trouble focusing, thinking clearly, or staying awake. Their behavior and emotions may also change rapidly. Unlike dementia, which develops slowly over time, delirium comes on quickly and often signals an underlying health issue.

Common Causes?

Delirium is often triggered by something physical or medical. Some common causes include:

• Infections – such as urinary tract infections (UTIs) or pneumonia
• Medication side effects or interactions
• Alcohol or drug withdrawal
• Dehydration or poor nutrition
• Severe pain
• Surgery or anesthesia, especially in older adults
• Sleep deprivation
• Brain injuries, strokes, or tumors
• Low oxygen levels or breathing problems
• Electrolyte imbalances
• Organ failure (kidneys, liver, heart)

Risk Factors?

While anyone can develop delirium, certain factors increase the risk:

• Older age, especially over 65
• Dementia or cognitive decline
• Being hospitalized, especially in the ICU
• Having multiple health conditions
• Vision or hearing problems
• Recent surgery or major illness
• Use of certain medications (sedatives, painkillers, sleeping pills)

Signs and Symptoms?

Delirium symptoms can vary and may come and go throughout the day. The three main types are hyperactive, hypoactive, and mixed delirium.

Common symptoms include:

• Sudden confusion or disorientation
• Trouble concentrating or following conversations
• Hallucinations (seeing or hearing things that aren’t there)
• Restlessness or agitation
• Drowsiness or sluggishness (in hypoactive delirium)
• Memory problems
• Mood swings or emotional outbursts
• Slurred speech
• Sleep disturbances
• Unusual or inappropriate behavior

In some cases, delirium may be mistaken for dementia, depression, or other mental health conditions, so proper evaluation is important.

When to See a Doctor?

Delirium is a medical emergency. If someone suddenly becomes confused, disoriented, or behaves differently than usual—especially after illness, surgery, or hospitalization—seek medical help right away. The sooner the cause is identified and treated, the better the outcome.

Diagnosis and Treatment?

Doctors diagnose delirium by reviewing medical history, performing physical and neurological exams, and asking about recent medications or illnesses. Blood tests, brain scans, and other investigations may be used to find the cause.

Treatment focuses on:

• Identifying and treating the underlying cause (e.g., infection, dehydration, medication issues)
• Stopping or adjusting medications that may be contributing
• Supportive care – making the person feel safe and oriented
• Hydration and nutrition
• Monitoring in a quiet, calm environment
• Reassurance and presence of familiar people or objects

Delirium usually improves once the underlying cause is treated, but recovery may take days or weeks depending on the individual’s overall health.

Prevention Tips

While not all cases of delirium can be prevented, some steps can help reduce the risk—especially in hospitals or for older adults:

• Stay well-hydrated and nourished
• Manage chronic health conditions
• Avoid sudden medication changes
• Encourage regular sleep and rest
• Keep glasses and hearing aids within reach
• Provide familiar objects, faces, or routines
• Reduce noise and confusion in the care environment
• Watch closely for early signs of confusion