Causes of Confusion

Medically reviewed by:

Dr Eddie Roche - Medical Officer

Updated: Aug 18, 2021

Next review: Aug 18, 2022

There are a number of things that can cause confusion, varying from simple mineral or vitamin deficiencies to underlying medical conditions.

It can be very frightening if you or a loved one is experiencing confusion, so it’s good to speak to a doctor to get reassurance and treatment.

The symptoms of confusion will vary from person to person, and it can come on very quickly, or more slowly over time.

Confusion can also cause unusual and aggressive behavior, which is another reason why it’s good to speak to a doctor, whether it’s yourself or someone that you know who is confused.

Some causes of confusion can include:

Dehydration - Not taking in enough water can lead to dehydration and an imbalance of salts in your body. This leads to the body not being able to function correctly, which can lead to confusion and become quite serious if left untreated.
Concussion - A brain injury, or concussion, is usually caused by a head trauma and this can lead to impaired judgement or co-ordination. Confusion symptoms from a concussion may not present themselves until a few days after the initial injury.
Medication - There are some medications that can lead to confusion symptoms. Withdrawal from a certain medication or taking too much of a prescribed medicine could cause confusion.
Alzheimer’s disease – This is the most common cause of dementia (see below). It’s a physical disease that affects the brain gradually, over time.
Dementia - If you or someone you care about is confused for a long time, and is older, it could be a sign of dementia. This is caused by a decline in brain function. If you think it could be dementia, speak to a doctor, who can diagnose and suggest treatment.
Delirium – This is a sudden change in the way a person’s brain is working. It could be caused by withdrawal of alcohol, drugs or medication, or if a health problem or infection suddenly gets worse.
Substance abuse – Alcohol and illegal drugs can cause confusion in people.
Infection – Urinary Tract Infections (UTIs), respiratory infections or sepsis can cause confusion.
Fever - Seek medical treatment urgently if the person is suffering from a high fever and showing signs of confusion.
Stress, anxiety or depression – These mental health conditions may lead to periods of confusion.
Stroke or TIA (mini stroke) – Strokes can cause slurred speech, which can be interpreted as confusion. If the sufferer also shows other signs of a stroke, seek urgent medication. This includes their face drooping on one side, not being able to smile, being unable to lift their arms or numbness in their arms or legs.

These are some of the common causes of confusion. However, there are many other things that could lead to the onset of symptoms. A lack of oxygen, a sudden drop of body temperature or a lack of sleep can affect the function of the brain leading to a confused state.

Dr Eddie Roche - Medical Officer

What causes confusion?