Encephalopathy vs Encephalitis

Encephalopathy and encephalitis both affect the brain, but they have different causes, symptoms, and treatments.

Encephalopathy refers to any condition that causes changes in brain function or structure. It could be caused by many things, such as infections, brain tumors, and prolonged exposure to toxic substances. The hallmark feature of encephalopathy is altered mental status, which means you become confused and don't act like yourself.

On the other hand, encephalitis occurs when the brain is inflamed as a result of an infection or autoimmune disease. Encephalitis is diagnosed in 10 to 15 people per 100,000 each year in the United States. It can affect anyone, but is most common in younger people. Symptoms of encephalitis include headaches, stiff neck, confusion, and seizures.

Doctor viewing digital tablet with CT scan result of brain, looking for abnormalities

Andrew Brookes / Getty Images


Encephalopathy Causes

Numerous things can cause encephalopathy, including:

  • Metabolic dysfunction: Chemical imbalance in the blood that is a result of illness or organs not working as well as they should can lead to metabolic encephalopathy.
  • Prolonged toxic exposure: Exposure to neurotoxic agents like solvents, drugs, radiation, paints, industrial chemicals, or certain metals can cause toxic encephalopathy.
  • Repeat head trauma: Repeat traumatic brain injury can lead to chronic traumatic encephalopathy.
  • Poor nutrition: A deficiency of thiamine, also called vitamin B1, can cause Wernicke's encephalopathy.
  • Lack of oxygen or blood flow to the brain: This can result in hypoxic ischemic encephalopathy.

Other conditions can also lead to encephalopathy. For example, Hashimoto's disease, a common autoimmune thyroid disease, may lead to a form of encephalopathy called Hashimoto's encephalopathy. Liver disease may also affect brain functioning and result in hepatic encephalopathy.

Encephalitis Causes

Possible causes of encephalitis include:

  • Viruses: Infections from herpes simplex viruses, enteroviruses (which cause gastrointestinal illnesses), human immunodeficiency virus (HIV), West Nile virus, and tick-borne viruses lead to viral encephalitis. This is the most common cause.
  • Problem with the immune system: The immune system can mistakenly attack the brain, causing autoimmune encephalitis.
  • Bacteria and parasites: These germs can cause bacterial encephalitis. An example is Lyme disease.


Symptoms of encephalopathy and encephalitis can range from mild to severe.

Encephalopathy Symptoms

Depending on the cause and type of encephalopathy someone has, symptoms may include:

  • Confusion
  • Progressive memory loss
  • Personality changes
  • Inability to concentrate
  • Lethargy
  • Progressive loss of consciousness
  • Myoclonus (involuntary twitching of a muscle or group of muscles)
  • Nystagmus (rapid, involuntary eye movement)
  • Tremor
  • Dementia
  • Seizures
  • Loss of the ability to swallow or speak

When to See a Doctor

Call your doctor or seek emergency medical attention right away if you experience any symptoms of encephalopathy or encephalitis.

Encephalitis symptoms

Encephalitis symptoms may appear gradually and are mild, but symptoms often rapidly increase and get more serious.

Common symptoms of encephalitis include:

  • Fever
  • Headache
  • Joint pain
  • Muscle weakness
  • Nausea
  • Stiff neck
  • Behavior changes
  • Confusion
  • Difficulty speaking or moving
  • Loss of consciousness
  • Memory issues
  • Seizures
  • Photophobia (sensitivity to light)


Diagnosing encephalopathy and encephalitis is a complex process. Your healthcare providers use similar tests and evaluations to the two conditions.

Diagnosing Encephalopathy

Diagnosis of encephalopathy includes analyzing symptoms and ruling out possible other conditions with the following tools:

  • Physical exam
  • Mental status exam and neurological exam
  • Blood and urine tests
  • Lumbar puncture (spinal tap) to test your cerebrospinal fluid
  • Imaging, including CT and MRI of the brain
  • Electroencephalogram, which records electrical activity in the brain

Diagnosing Encephalitis

Each part of the diagnosis process can help your doctor see signs and symptoms of an inflamed brain:

  • CT scan of the brain to make sure that the symptoms aren’t caused by another cause
  • Spinal tap to look for infections, like bacteria and viruses
  • Electroencephalogram to look for seizures 
  • An MRI to identify inflammation in the brain
  • Blood, urine, and stool tests to check for signs of an infection


Treatment for both encephalopathy and encephalitis is crucial to avoid worsening symptoms, complications, and even fatal outcomes.

Treating Encephalopathy

Depending on the type and symptoms, encephalopathy can be treated in a variety of ways, including medications and surgery.

Common treatments include:

  • Medications to alleviate symptoms, including anticonvulsants for seizures
  • Dietary changes
  • Cognitive training
  • Dialysis or organ replacement surgery in people with kidney failure or liver transplant or in those with hepatic encephalopathy

Additional therapies or medications may be needed depending on the severity and complications related to your encephalopathy.

Treating Encephalitis

Depending on the type of encephalitis, treatments include:

  • Antibiotics to treat bacterial infections
  • Antiviral medications for viral infections
  • Anticonvulsants for seizures.
  • Breathing assistance, including supplemental oxygen or a breathing machine (mechanical ventilation)
  • Immunomodulators, which can lower immune system activity
  • Steroids to reduce swelling and brain pressure

The impact of autoimmune and viral encephalitis on brain functioning differs from person to person. Some people make a complete recovery, but others may have long-lasting symptoms. These include balance and coordination issues, difficulty concentrating, fatigue, hearing loss, memory problems, and difficulty speaking.


Prevention of encephalopathy and encephalitis starts with knowing the causes and taking action to lower risk.

Preventing Encephalopathy

Encephalopathy isn't always preventable, but there are risk factors and causes that you can control to lower risk. For example, staying up to date with your vaccinations and avoiding contact sports to prevent head trauma may help mitigate your risk of having encephalopathy.

Additionally, you can lower your risk by eating a balanced diet, reducing alcohol consumption, avoiding toxins, and adhering to your treatments for all pre-existing conditions.

Preventing Encephalitis

Similar to encephalopathy, you can prevent encephalitis by understanding the causes and risk factors. Avoiding the viruses that can cause encephalitis is critical. That means getting vaccinated to avoid infection, such as the measles, mumps, and rubella vaccines.

Don't forget that bugs and animals can carry viruses, so protection against mosquitoes and ticks can also help lower your risk of getting encephalitis.


Encephalopathy and encephalitis may be different, but they are both conditions that require immediate medical attention as soon as you notice the signs and symptoms. Getting treatment early can help prevent serious long-term complications.

5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. National Institute of Neurological Disorders and Stroke. Encephalopathy information page.

  2. Johns Hopkins Medicine. Encephalitis.

  3. Lian X, Wu M, Fan H, Zhang Y, Sun P. Wernicke's encephalopathy due to malnutrition and parenteral nutrition in a patient with cerebral infarction: A case report. Medicine (Baltimore). 2020 Apr;99(16):e19799. doi:10.1097/MD.0000000000019799

  4. Allen KA, Brandon DH. Hypoxic ischemic encephalopathy: pathophysiology and experimental treatments. Newborn Infant Nurs Rev. 2011 Sep 1;11(3):125-133. doi:10.1053/j.nainr.2011.07.004

  5. Cleveland Clinic. Encephalitis.

By Kimberly Charleson
Kimberly is a health and wellness content writer crafting well-researched content that answers your health questions.