What Causes Confusion?

Medically reviewed by George Krucik, MD, MBA

Confusion is a symptom that makes you feel as if you can’t think clearly. You might feel disoriented and have a hard time focusing or making decisions. Confusion is also referred to as disorientation. In its extreme state, it’s referred to as... Read More

Confusion is a symptom that makes you feel as if you can’t think clearly. You might feel disoriented and have a hard time focusing or making decisions. Confusion is also referred to as disorientation. In its extreme state, it’s referred to as delirium.

If you or someone you care about is confused for a long period of time, dementia might be the reason. Dementia is a condition caused by brain function decline that results in the loss of your ability to perform everyday functions. It also affects judgment and behavior.

What Are the Signs of Confusion?

Noticing the symptoms of confusion when they first appear will help you or your loved one get prompt treatment. Some signs of confusion are:

  • slurring words or having long pauses during speech
  • abnormal or incoherent speech
  • lack of awareness of location or time
  • forgetting what a task is while it is being performed
  • sudden changes in emotion, such as sudden agitation

If you’re the one experiencing signs of confusion, it might be a good idea to call a friend or loved one for help. If you are confused, you might need help with things that you could do on your own before.

When to See a Doctor

If you or someone you know starts showing signs of confusion, call a doctor. Confusion can have many causes, including injury, infection, substance use, and medications. It’s important to find out what the underlying cause of the confusion is so that it can be treated.

Your doctor will ask you or your loved one to indicate when the confusion started and when you last exhibited “normal” thinking and behavior. Being able to describe the characteristics and duration of the confusion will help your doctor diagnose its cause.

People suffering from confusion can sometimes act aggressively or unpredictably. A person experiencing confusion should be closely observed and protected from harming themselves or others. If their confusion is extreme or reaching the point of delirium, your doctor may recommend admitting them to a hospital.

If confusion follows a head injury or trauma, it could be a possible concussion and you should call 9-1-1 or go to an emergency room right away. It’s especially important to call a doctor if you notice confusion alongside the following symptoms:

  • dizziness
  • rapid heart beat
  • clammy skin
  • fever
  • headache
  • shivering
  • irregular breathing

What Are the Underlying Causes of Confusion?

There are a number of factors that can cause confusion, from serious health problems to vitamin deficiencies. Alcohol intoxication is a common cause of confusion. Other causes include:


A concussion is a brain injury that occurs as a result of head trauma. A concussion can change someone’s level of alertness as well as their judgment, coordination, and speech. You might pass out if you have a concussion, but it’s also possible to have one and not know it. You may not start to feel confusion due to a concussion until a few days after the injury.


Your body loses fluids everyday through sweating, urination, and other bodily functions. If you don’t replace these fluids often enough, you could eventually become dehydrated. This can affect the amount of electrolytes (minerals) your body contains, which can cause problems with your body’s ability to function.


Certain medications can cause confusion. Not taking medications as prescribed can also cause confusion, as can withdrawal from a medication that you recently stopped taking.

Confusion is the most common sign of medical complications related to cancer treatment. Chemotherapy, which uses chemicals to kill cancer cells, often affects healthy cells along with cancerous ones. Chemotherapy can cause damage to your nerves, which can affect your brain’s functions and cause confusion.

Other Potential Causes

Confusion can be caused by a number of different factors. Other potential causes include:

  • fever
  • infection
  • low blood sugar
  • not getting enough sleep
  • lack of oxygen
  • rapid drop in body temperature
  • depression

What Can Be Done About Confusion?

For short-term cases of mild confusion caused by nutritional imbalances, dehydration, or sleep deprivation, you or your loved one might find relief in treatment at home.

If the cause of your confusion is low blood sugar, drinking a sweetened beverage or eating a small piece of candy may be all you need to relieve your symptoms. If your confusion is caused by dehydration, drinking water or electrolyte drinks can help relieve your symptoms.

However, confusion due to a head injury requires immediate medical attention. If your confusion is caused by a concussion, your doctor will decide when it’s best to release you from treatment. They will give you advice on how to structure your lifestyle around treating your concussion, such as eating light foods and avoiding alcohol for some time. You may not need to stay in bed, but you should have someone check on you every few hours if you think you may fall asleep within the first 12 hours of having a concussion.

Because there are many serious conditions that can cause confusion, medical attention is often required. Do not hesitate to call a doctor if a loved one suddenly displays signs of confusion.

It can be frightening when a loved one is experiencing confusion. Until a doctor determines the cause of the confusion, the most important thing you can do is stay with the person and observe how they are acting. Your description of their behavior will be an important tool in determining what’s causing their confusion so they can be treated.

Medically reviewed by Deborah Weatherspoon, Ph.D., MSN, RN, CRNA on November 12, 2015Written by The Healthline Editorial Team

80 possible conditions

This feature is for informational purposes only and should not be used to diagnose. Please consult a healthcare professional if you have health concerns.

CMS Id: Client Version: 99dc39eb23b1104ff17acbdf49017416ec9b327d Build Number: 13061