Brain fog is a term used to describe an overall feeling of mental fogginess. This includes forgetfulness, concentration problems, and confusion. It’s a state of generally disorganized thinking.

Studies show that about half of those with hepatitis C experience neuropsychiatric symptoms such as brain fog. Related symptoms include weakness, irritability, and fatigue. While these complaints may seem minor, they can make it hard to perform daily tasks.

Hepatitis C affects the liver and is a condition that develops from an infection with the hepatitis C virus. Your liver is responsible for removing harmful substances from your blood, among other duties. When it doesn’t function properly, it can affect the entire body, including your brain.

Symptoms of brain fog are more likely to occur in people with advanced hepatitis C or in those who have developed cirrhosis. Other symptoms of hepatitis C can contribute to that foggy feeling. Treatment can also contribute to this symptom. This may include direct-acting antiviral (DAA) therapy with or without ribavirin. An older medication, interferon, used to have a significant number of side effects, but this medication is no longer typically used.


Fatigue is a common symptom of hepatitis C. DAA therapy causes insomnia in a minority of people. Lack of sleep is a contributing factor in headaches, moodiness, and depression. Another medication, ribavirin, can create sleep disturbances and is known to cause fatigue. All of these can contribute to brain fog.


Having hepatitis C in itself may cause a certain level of anxiety. DAA therapy can also cause you to feel edgy and anxious.

Anger, irritability, moodiness

People on DAA therapy tend to anger more easily than they normally would. Ribavirin can cause irritability and general moodiness.

Sadness or depression

Sadness may be a result of having hepatitis C, and it’s a common side effect of ribavirin. It will usually subside within weeks after treatment ends. Talk with your doctor if you notice symptoms of depression. Your medication dosages may need to be adjusted, and antidepressants may need to be added to your treatment plan.

Memory, concentration, and confusion

Trouble remembering things and maintaining concentration are side effects of ribavirin. These effects may also lead to general confusion.

Other symptoms of hepatitis C brain fog

Hepatitis C can also cause physical symptoms that may contribute to brain fog, such as:

  • muscle aches
  • stomachaches
  • fever
  • loss of appetite

Hepatic encephalopathy is more than just brain fog. It’s a condition in which brain function is harmed because the liver is unable to remove toxins from the blood. This allows harmful chemicals to build up in the bloodstream. It generally occurs in people who have advanced hepatitis, cirrhosis, or another chronic liver disease.

Symptoms of hepatic encephalopathy include:

  • worsening brain fog
  • musty or sweet breath
  • trouble with small hand movements

More severe signs include:

  • hand or arm shaking
  • major personality changes
  • slurred speech

People can become sluggish, unconscious, or slip into a coma. This is a medical emergency that requires immediate hospitalization.

Side effects of medications may improve after your body adjusts. If not, dosage adjustments, changes in medications, and additional therapies may help ease brain fog.

Complementary therapies like meditation, breathing exercises, and yoga may help ease some symptoms and side effects. Making changes to your sleep patterns, diet, and exercise may help improve your overall health and sense of well-being.

If you’re experiencing brain fog, have a conversation with your doctor.