Find out about the main signs and symptoms of encephalitis, and when to get medical advice.
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.
The first symptoms of encephalitis can be similar to 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.
More severe symptoms develop when the brain is affected, such as:
- confusion or disorientation
- seizures (fits)
- changes in personality and behaviour, such as feeling very agitated
- 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
- vision problems
- 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 when a 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 emergency that needs to be seen in hospital as soon as possible.
Read about how encephalitis is diagnosed and how encephalitis is treated.