India
Psychiatry · 4 min read

Delirium

Learn about Delirium, its reported features, relevant specialists, and questions to discuss at a medical consultation.

Compiled from public sources
Text selected and arranged from MedlinePlus (US National Library of Medicine) health topic. It describes the condition as those sources do; it has not been rewritten for India.
01 Oct 2026
Not medically reviewed
No registered doctor has reviewed this page. Use it to decide who to see and what to ask — not to diagnose or treat.
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This is not medical advice. If symptoms are severe, sudden or getting worse, call 112 (or 108 for an ambulance) or go to the nearest emergency department.

The sources compiled here do not cover: onset, prevalence. Ask the treating doctor about these.

What is delirium?

From: MedlinePlus, National Library of Medicine

Delirium is a mental state in which you are confused, disoriented, and not able to think or remember clearly. It usually starts suddenly. It is often temporary and treatable.

There are three types of delirium:

  • Hypoactive, when you are not active and seem sleepy, tired, or depressed
  • Hyperactive, when you are restless or agitated
  • Mixed, when you change back and forth between being hypoactive and hyperactive

What causes delirium?

From: MedlinePlus, National Library of Medicine

There are many different problems that can cause delirium. Some of the more common causes include:

  • Advanced cancer.
  • Alcohol or drugs, either from intoxication or withdrawal. This includes a serious type of alcohol withdrawal syndrome called delirium tremens. It usually happens to people who stop drinking after years of alcohol use disorder (AUD).
  • Dehydration and electrolyte imbalances.
  • Dementia.
  • Hospitalization, especially in intensive care.
  • Infections, such as urinary tract infections, pneumonia, and the flu.
  • Medicines. This could be a side effect of a medicine, such as sedatives or opioids. Or it could be from withdrawal after stopping a medicine.
  • Metabolic disorders.
  • Organ failure, such as kidney or liver failure.
  • Poisoning.
  • Serious illnesses.
  • Severe pain.
  • Sleep deprivation.
  • Surgeries, including reactions to anesthesia.

Who is more likely to get delirium?

From: MedlinePlus, National Library of Medicine

Certain factors put you at risk for delirium, including:

  • Being in a hospital or nursing home
  • Having dementia
  • Having a serious illness or more than one illness
  • Having an infection
  • Older age
  • Having surgery
  • Taking medicines that affect the mind or behavior
  • Taking high doses of pain medicines, such as opioids

What are the symptoms of delirium?

From: MedlinePlus, National Library of Medicine

The symptoms of delirium usually start suddenly, over a few hours or a few days. They often come and go. The most common symptoms include:

  • Changes in alertness (usually more alert in the morning, less at night)
  • Changing levels of consciousness
  • Confusion
  • Disorganized thinking, talking in a way that doesn't make sense
  • Disrupted sleep patterns, sleepiness
  • Emotional changes: anger, agitation, depression, irritability, overexcitement
  • Hallucinations and delusions
  • Memory problems, especially with short-term memory
  • Trouble concentrating

How is delirium diagnosed?

From: MedlinePlus, National Library of Medicine

Your health care provider may use many tools to make a diagnosis:

Delirium and dementia have similar symptoms, so it can be hard to tell them apart. You can also have both at the same time. The differences between them are that:

  • A medical history, which includes asking about your symptoms
  • Physical and neurological exams
  • Mental status testing, which checks for problems with your thinking and alertness
  • Lab and diagnostic imaging tests
  • Delirium starts suddenly and can cause hallucinations. It is mainly a problem with attention and staying alert. The symptoms may get better or worse and can last for hours or weeks.
  • Dementia develops slowly and does not cause hallucinations. It usually starts with memory loss. The symptoms don't change often, like they can with delirium. Dementia almost never gets better.

What are the treatments for delirium?

From: MedlinePlus, National Library of Medicine

Treatment of delirium focuses on the causes and symptoms of delirium. The first step is to identify the cause. Often, treating the cause will lead to a full recovery. The recovery may take some time - weeks or sometimes even months. In the meantime, there may be treatments to manage the symptoms, such as:

  • Controlling the environment, which includes making sure that the room is quiet and well-lit, having clocks or calendars in view, and having family members around
  • Medicines, including those that control aggression or agitation and pain relievers if there is pain
  • If needed, making sure that the person has a hearing aid, glasses, or other devices for communication

Can delirium be prevented?

From: MedlinePlus, National Library of Medicine

Treating the conditions that can cause delirium may reduce the risk of getting it. Hospitals can help lower the risk of delirium by avoiding sedatives and making sure that hospital rooms are kept quiet, calm, and well-lit. It can also help to have family members around and to have the same staff members treat the person each day (if possible).

Which doctor should you see?

The suggested department for discussing Delirium is Psychiatry, with a psychiatrist as the relevant type of clinician. Urgent in-person medical assessment; emergency department if severe or deteriorating.

This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.

How to prepare for an assessment

Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.

Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.

  • How are symptoms affecting safety, sleep, relationships and everyday function?
  • What roles could psychological treatment, medicines or support services have?
  • Who should be contacted if safety or functioning deteriorates?

Treatment discussions and follow-up

Where the source describes treatments, these are an overview of possible care, not a prescription for an individual. Ask which option applies to the confirmed diagnosis, what benefit is expected, what adverse effects to watch for and how progress will be assessed. Availability, approvals and local practice can differ from the country described in the source.

Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.

When to seek emergency help

Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.

Find a doctor for Delirium

This condition is usually assessed by a psychiatrist. Every profile shows the doctor’s registration and what has been checked.

All psychiatry conditions →

Sources

Source: MedlinePlus, National Library of Medicine. Orphadata Science: Free access data from Orphanet. © INSERM 1999; July 2026 data, CC BY 4.0. This product uses the Human Phenotype Ontology (hp/releases/2026-09-01). Only sources listed for this article apply. Source material has been selected and arranged; HPO definitions are reproduced without alteration. No source organisation endorses this compilation. Köhler S et al. The Human Phenotype Ontology project: linking molecular biology and disease through phenotype data. Nucleic Acids Research 2014;42(D1):D966–D974. doi:10.1093/nar/gkt1026.

General information, not advice about your situation. Errors can be reported through the corrections process. Reference TDI-C-0713.