Mental confusion

Mental confusion (often simply called confusion) is a symptom. People suffering from it have problems finding their way around in the world. They have troubles remembering who they are, where they are, or what time (or day of the week) it is. Additionally, they may have trouble remembering things or memorizing new things. This may be linked to problems focusing their attention. Confusion can also be a sign of someone being sick with various illnesses when it's coupled with things like fever, chills, or exhaustion.

Mental confusion

ICD-10	R41.0
ICD-9	298.9
MedlinePlus	003205
MeSH	D003221

Image from a medical textbook in 1913 showing a confused woman.

Medical causes of confusion

Confusion can be caused by many different medical problems.

There are both acute and chronic causes of confusion.

Acute causes of confusion

Acute causes of confusion usually come on suddenly, and doctors may be able to fix some of them.

In medicine, the acronym AEIOU-TIPS is used to remember the most common causes of confusion that comes on suddenly (over hours or days, not years):^[1]

• Alcohol (being drunk) or Acidosis (having too much acid in the blood, which poisons the body)
• Environmental causes (like being very cold) or Epilepsy (being confused after a seizure)
• Infection (like meningitis, an infection of the brain's lining)
• Overdose (taking too much medicine or too many illegal drugs)
• Uremia (poisons building up in the blood because of kidney problems) or Underdose (not taking enough prescribed medicine)
• Trauma (injury, especially to the head)
• Insulin (confusion because of a blood sugar emergency - blood sugar is either too low or much too high)
• Psychogenic (when mental illness causes confusion)
• Stroke (when not enough blood and oxygen gets part of the brain)

Confusion can also happen when the brain is not getting enough blood and oxygen. For example, this can happen because of:^[1][2]

• Low blood pressure (when the heart is not pumping hard enough to get blood and oxygen to the brain)
• If the heart is beating too slow, or too fast, or not regularly (making the heart unable to get blood and oxygen up to the brain)
• A breathing problem that makes it impossible to get enough oxygen into the body (like a bad asthma attack, or chronic obstructive pulmonary disease (COPD)). COPD can also cause a related mental disorder called Depression (mental illness)

Chronic causes of confusion

Chronic causes of confusion usually come on less suddenly and last for a long time (months or years). For example:^[2]

• Dementia or Alzheimer's disease can cause a person to be confused most of the time, or all of the time
• Traumatic brain injury, or any other kind of damage to the brain
• A brain tumor

References

1. Stephen J. Traub, MD, FACEP (April 25, 2014). Advanced Practice Provider Academy: The Altered Patient (PDF) (Report). American College of Emergency Physicians. Archived from the original (PDF) on November 6, 2015. Retrieved December 25, 2015.{{cite report}}: CS1 maint: multiple names: authors list (link)
2. "Altered Mental Status". www.med.unc.edu. University of North Carolina School of Medicine. Retrieved December 25, 2015.