“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.

Causes and Types

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.