Meningitis is difficult to diagnose. It comes on quite suddenly and can be easily confused with the flu because many of the symptoms are the same.

If you notice the slightest suggestion of meningitis, especially if it's a young child, get help immediately - even if this means going to the accident and emergency (A&E) department of your local hospital in the middle of the night.

Do not wait for the purple rash to appear. It doesn’t always happen. Meningitis is fast moving and dangerous and needs to be taken seriously. It doesn’t matter if you're wrong. Let the doctors decide if it is serious.

In cases of suspected meningitis, treatment will usually begin before the diagnosis has been confirmed. This is because some of the tests can take several hours to complete and it could be dangerous to delay treatment for that amount of time.

Diagnostic tests for meningitis include:

• A blood test - to check for bacteria or viral infections.
• A CT scan - to assess the level of pressure on the brain and look for other abnormailities in the brain.
• A lumbar puncture - this involves taking a sample of cerebrospinal fluid (CSF) from the base of the spine and checking it for the presence of bacteria or viruses.

If there are signs of increased pressure on the brain then a lumbar puncture will need to be delayed. This is because removing some of the CSF could lead to a further increase of pressure and neurologic complications.