ICD-10 Diagnosis Code R40.4

Transient alteration of awareness

Diagnosis Code R40.4

ICD-10: R40.4
Short Description: Transient alteration of awareness
Long Description: Transient alteration of awareness
This is the 2017 version of the ICD-10-CM diagnosis code R40.4

Code Classification
  • Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
    • Symptoms and signs involving cognition, perception, emotional state and behavior (R40-R46)
      • Somnolence, stupor and coma (R40)

Information for Medical Professionals

According to ICD-10-CM guidelines this code should not to be used as a principal diagnosis code when a related definitive diagnosis has been established.
Convert to ICD-9 Additional informationCallout TooltipGeneral Equivalence Map
The ICD-10 and ICD-9 GEMs are used to facilitate linking between the diagnosis codes in ICD-9-CM and the new ICD-10-CM code set. The GEMs are the raw material from which providers, health information vendors and payers can derive specific applied mappings to meet their needs.
  • 780.02 - Trans alter awareness

  • Decreased level of consciousness
  • Feeling faint

Information for Patients


Delirium is a condition that features rapidly changing mental states. It causes confusion and changes in behavior. Besides falling in and out of consciousness, there may be problems with

  • Attention and awareness
  • Thinking and memory
  • Emotion
  • Muscle control
  • Sleeping and waking

Causes of delirium include medications, poisoning, serious illnesses or infections, and severe pain. It can also be part of some mental illnesses or dementia.

Delirium and dementia have similar symptoms, so it can be hard to tell them apart. They can also occur together. Delirium starts suddenly and can cause hallucinations. The symptoms may get better or worse, and can last for hours or weeks. On the other hand, dementia develops slowly and does not cause hallucinations. The symptoms are stable, and may last for months or years.

Delirium tremens is a serious type of alcohol withdrawal syndrome. It usually happens to people who stop drinking after years of alcohol abuse.

People with delirium often, though not always, make a full recovery after their underlying illness is treated.

  • Delirium
  • Delirium tremens

[Read More]

Mental Disorders

Also called: Mental illness

Mental disorders include a wide range of problems, including

  • Anxiety disorders, including panic disorder, obsessive-compulsive disorder, post-traumatic stress disorder, and phobias
  • Bipolar disorder
  • Depression
  • Mood disorders
  • Personality disorders
  • Psychotic disorders, including schizophrenia

There are many causes of mental disorders. Your genes and family history may play a role. Your life experiences, such as stress or a history of abuse, may also matter. Biological factors can also be part of the cause. A traumatic brain injury can lead to a mental disorder. A mother's exposure to viruses or toxic chemicals while pregnant may play a part. Other factors may increase your risk, such as use of illegal drugs or having a serious medical condition like cancer.

Medications and counseling can help many mental disorders.

  • Adjustment disorder
  • Conversion disorder
  • Illness anxiety disorder
  • Somatic symptom disorder

[Read More]
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