What Causes Altered Mental Status?

Medically Reviewed By Ifeanyi Olele, DO, MBA, MS

Altered mental status describes a change in cognitive function. Changes can include delirium, hallucinations, and confusion. Common causes are infection, medications, and drug and alcohol use. Altered mental status describes a change in a person’s mental function. The causes of the changes are varied, and often diagnosing the underlying source can be challenging.

Altered mental status is a common occurrence in hospitalized older adults. It’s also often seen in adults in the emergency department.

This article discusses the causes of altered mental status and explains the symptoms and types. It also examines how altered mental status is diagnosed and treated.

Key facts about altered mental status

  • Altered mental status means a change in a person’s mental function.
  • Common causes include infection, trauma, and ingesting toxins.
  • Symptoms vary and include behavioral changes, cognitive impairment, and emotional disturbances.
  • The types of altered mental status include psychosis, dementia, and delirium.

What causes altered mental status?

Illustration of a female sitting on a stool in a spotlight. In the darker parts there is a blue tone and a large ball of string unravelling.
Illustration by Maya Chastain

Altered mental status can present in many ways, including in:

  • consciousness
  • appearance
  • mood
  • motor activity
  • cognitive function, which includes memory, reasoning, and attention

The reason for altered mental status can include infection, trauma, and toxin ingestion.

The most common Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source causes in infants and children include infection, toxin ingestion, and metabolic changes. In young adults, the common causes are generally trauma and toxin ingestion. Older adults typically experience altered mental status due to:

  • stroke
  • infection
  • medication interactions
  • changes to their living environment

The list of causes of altered mental state is long but here are some from common categories:

Central nervous system incidents

Incidents involving the central nervous system that can cause altered mental status include:


Common medications that can cause altered mental state include:

Metabolic disturbances

Metabolic disturbances that can cause altered mental status include:


Infections that can cause altered mental status include:

Medical conditions

Other conditions that can cause altered mental status include:


Alcohol and most illegal drugs can result in an altered mental status. This can happen both with intoxication or withdrawal.

What are the symptoms of altered mental status?

Symptoms depend on the underlying cause and the type of altered mental status.

The symptoms of altered mental status include:

  • Behavioral changes: These changes may include hallucinations, difficulty sleeping, and agitation.
  • Cognitive impairment: Changes to cognitive impairment include disorientation, difficulty with speech or rambling, and poor memory. It may also include difficulty reading or writing.
  • Emotional disturbances: Emotional disturbances can range from depression to mania. Some disturbances include anxiety, irritability, and elation. These can shift quickly and significantly.
  • Reduced environmental awareness: This reduced awareness may include having difficulty focusing or being withdrawn.

Contact a doctor or seek medical care if you or someone you know experiences these symptoms.

What are the types of altered mental status?

The three types of altered mental status are delirium, dementia, and psychosis.


Delirium is considered a medical emergency. It’s more commonly seen in adults over 70 years old Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source and is usually a result of stress on the central nervous system. Underlying conditions, medications, and toxins can cause delirium.

The signs of delirium include:

  • change in mental status that may fluctuate
  • decreased ability to follow conversations or pay attention
  • disorganized thinking, including issues with memory or language
  • altered levels of consciousness, including hypervigilance and drowsiness


Dementia is a slow, progressive condition that causes Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source a loss of mental capacity.

One of the most common types of dementia is Alzheimer’s disease. As dementia progresses, people with the condition show signs of decreasing performance in social situations, changes in personality, and an inability to care for themselves.

Learn more about dementia.


Psychosis is a disruption of thoughts and perceptions. People with the condition have difficulty recognizing what is real and what is not.

Though there’s a range of symptoms, people with with psychosis usually experience either hallucinations or delusions.

  • Hallucinations: Hallucinations involve seeing, hearing, or feeling something that’s not there, including:
    • hearing voices
    • experiencing sensations or unexplained feelings
    • seeing distortions or glimpses of people or objects that are not there
  • Delusions: Delusions are ideas and beliefs not consistent with your culture, are not likely true, or may seem irrational. These include:
    • the belief that external forces are controlling your thoughts, feelings, and behaviors
    • the belief that trivial objects, events, or remarks have personal significance or meaning
    • the belief that you have special powers, are on a special mission, or that you are God

Read more about psychosis.

How is altered mental status diagnosed?

Altered mental status can be challenging to diagnose due to so many symptoms and underlying causes.

Reaching a diagnosis often begins with a clinician asking about medical history. If a person is experiencing altered mental status, this may not be easy. However, family members, friends, or caretakers can help.

Your doctor will also perform a physical exam to check for signs of possible conditions causing the altered mental status.

They may also use laboratory and diagnostic testing to help find the cause of altered mental status.

How is altered mental status treated?

Treatment will depend on an underlying cause but may include medication for a condition.

Often, treating the symptoms of the underlying cause will help with altered mental status as well. For more complex reasons, like dementia, the treatment will typically be ongoing.

Treatment for dementia usually involves medications to help manage symptoms and other conditions. It may also include therapies to help with memory and the ability to think.

Other frequently asked questions

Ifeanyi Olele, D.O, MBA, M.S., has reviewed these questions people frequently ask about altered mental status.

What is the most common cause of altered mental status?

In younger adults, the most common causes of altered mental status are the ingestion of toxins or trauma. In older adults, the most common causes are stroke, infection, or medication interaction.

What causes sudden changes in mental status?

There are many possible causes but can include the ingestion of toxins, infections, and some medications. Other causes include incidents that involve the central nervous system and metabolic disturbances.

Can anxiety cause altered mental status?

Some symptoms of anxiety can make you feel as though you are separate from yourself or reality. This is a form of altered mental status.


Altered mental status is a change in a person’s mental function. This can include behavioral changes, emotional disturbances, and changes in cognitive function. Common symptoms include hallucinations, disorientation, and mood changes.

There are many possible causes for altered mental status. These include ingesting toxins like alcohol and illegal drugs, infections, and psychiatric conditions.

Treatment for altered mental status usually involves treating the underlying cause. If you or someone you know is experiencing altered mental status, contact your doctor or seek medical care.

Was this helpful?
Medical Reviewer: Ifeanyi Olele, DO, MBA, MS
Last Review Date: 2023 Apr 3
View All Symptoms and Conditions Articles
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.