What Is Encephalopathy?

Medically Reviewed by Christopher Melinosky, MD on October 24, 2023
4 min read

"Encephalopathy" means damage or disease that affects the brain. It happens when there’s been a change in the way your brain works or a change in your body that affects your brain. Those changes lead to an altered mental state, leaving you confused and not acting like you usually do.

Encephalopathy is not a single disease but a group of disorders with several causes. It’s a serious health problem that, without treatment, can cause temporary or permanent brain damage.

It’s easy to confuse encephalopathy with encephalitis. The words sound similar, but they are different conditions. In encephalitis, the brain itself is swollen or inflamed. Encephalopathy, on the other hand, refers to the mental state that can happen because of several types of health problems. But encephalitis can cause encephalopathy.

There are two main types of encephalopathy: reversible and irreversible. Reversible causes include:

  • Hepatic encephalopathy. When your liver is unable to remove toxins from your blood as well as it should, they build up in your body. That makes it hard for your brain to work well. It can happen to people with a chronic liver disease like cirrhosis or after an overdose of acetaminophen or other medications.
  • Hashimoto’s encephalopathy. This type is linked to a thyroid condition called Hashimoto’s disease. The cause isn’t clear, but it may be that your immune system attacks your brain and changes the way it works.
  • Metabolic encephalopathy. This happens when another health condition, such as diabetes, liver disease, kidney failure, or heart failure, makes it hard for the brain to work. For example, if blood sugar gets too high in diabetes, it can lead to confusion and even a coma.
  • Infections of the brain, such as encephalitis or meningitis, or in another part of the body, such as a urinary tract infection. An extreme response to an infection, called sepsis, can also lead to encephalopathy.
  • Brain tumors
  • Long-term exposure to toxins like solvents, drugs, radiation, paints, industrial chemicals, and some metals
  • Nonconvulsive status epilepticus. This happens when you have seizures over and over in your brain, though they may not cause any physical symptoms.

Types of encephalopathy that are irreversible include:

  • Chronic traumatic encephalopathy. This condition is caused by repeated head injuries, which damage the brain. Today, it’s best known for its ties to high-impact sports like football and boxing.
  • Hypoxic-ischemic encephalopathy. It happens when your brain doesn’t get enough oxygen, which leads to brain damage. It can happen after cardiac arrest, carbon monoxide poisoning, drug overdose, or near-drowning.

The symptoms you have depend on the type and cause of your encephalopathy, but some of the most common ones are:

  • Confusion
  • Memory loss
  • Personality changes
  • Trouble thinking clearly or focusing

Some people will also have:

  • Trouble speaking
  • Muscle weakness or twitches they can’t control
  • Eye movements they can’t control
  • Tremors
  • Trouble swallowing
  • Sleepiness
  • Seizures

If you notice any of these symptoms in yourself or someone else, you should call your doctor or go to the emergency room.

To diagnose the disorder, your doctor will give you a physical exam and ask you about your medical history, especially any medications you’re taking. They also may give you some other tests, such as:

The treatment you need depends on what’s causing your encephalopathy. Your doctor could recommend:

  • Medications to stop seizures or reduce ammonia levels
  • Stopping a medication you’ve been taking
  • Changing the foods you eat
  • Nutritional supplements
  • Dialysis or an organ transplant if liver or kidney problems are causing your condition

Your outlook depends largely on whether your encephalopathy is reversible or irreversible.

Encephalopathy from head injuries, toxins, cardiac arrest, or lack of oxygen to the brain causes physical damage to the brain that is usually permanent. That means your mental state may not go back to what it was.

In reversible encephalopathy, such as from organ failure, metabolic conditions, or infections, symptoms usually go away when you fix the problem that’s causing them, and you may be able to regain your previous mental abilities. For example, if you have hepatic encephalopathy, clearing toxins from your blood can fix any issues you’re having with confusion, memory problems, or mood swings.