Symptoms of encephalitis may be mild to begin with, but can become more serious over hours or days.

Occasionally the symptoms may develop gradually over several weeks or even months.

Early symptoms

The first symptoms of encephalitis can be similar to Bird flu , such as:

  • a high temperature (fever) of 38C (100.4F) or above
  • a headache
  • feeling and being sick
  • aching muscles and joints

Some people may also have a spotty or blistery rash on their skin.

But these early symptoms don't always appear and sometimes the first signs of encephalitis may be the more serious symptoms listed below.

Serious symptoms

More severe symptoms develop when the brain is affected, such as:

  • confusion or disorientation
  • drowsiness
  • seizures (fits)
  • changes in personality and behaviour, such asfeeling veryagitated
  • difficulty speaking
  • weakness or loss of movement in some parts of the body
  • seeing and hearing things that aren't there ( hallucinations )
  • loss of sensation in certain parts of the body
  • involuntary eye movements, such as side-to-side eye movement
  • visionproblems
  • loss of consciousness

There may also be symptoms of meningitis , such as a severe headache, sensitivity to bright lights, a stiff neck and a spotty rash that doesn't fade whena glass is pressed against it.

When to get medical advice

Dial 999 immediately to request an ambulance if you or someone else has serious symptoms of encephalitis.

It's a medical emergencythat needs to be seen in hospital as soon as possible.

Read about how encephalitis is diagnosed and how encephalitis is treated .

Content supplied by the NHS Website

Medically Reviewed by a doctor on 20 Dec 2016