The set of guidelines used by neurologists to diagnose MS, known as the McDonald criteria, has recently been updated to reflect the latest research and our better understanding of MS.
The new revisions (finalised in 2024 and published in September 2025) widen the evidence that can be used to diagnose MS and include new guidance on diagnostic markers that can identify MS more accurately.
The 2024 criteria also provide a more unified approach for diagnosing relapsing and progressive disease courses in children through to older people. This signals a move towards thinking of MS as a single condition with similar biological changes, rather than as three separate types.
The changes to the McDonald criteria are likely to speed up diagnosis, make MS easier to diagnose, and reduce the chance of MS being diagnosed incorrectly.
If you’ve already been diagnosed with MS, the changes to the diagnostic criteria won’t affect your diagnosis.
If you’re currently going through investigations for MS, your neurologist may be able to confirm (or rule out) MS more quickly.
You can read the full details on the MS Trust website.
