Unlike many other diseases, there is no straightforward test for MS and none of the range of tests available to help doctors with a diagnosis of MS is 100 percent conclusive on its own. 

Early MS may present itself as a history of vague symptoms, which may occur sporadically over a prolonged period of time and could often also be attributed to a number of other medical conditions. Invisible or subjective symptoms are often difficult to communicate to doctors and health professionals and sadly it has not been uncommon for people with MS to be treated unsympathetically in the very early stages of diagnosis.

Even when a person shows a ‘classic’ pattern of MS-type symptoms, the symptoms must conform to agreed criteria before a doctor or neurologist can diagnose clinically ‘definite’ MS. These criteria (called the McDonald Criteria) are that two different areas of the central nervous system are affected, and that these effects have been experienced on at least two separate occasions of at least one month apart, supported by a magnetic resonance image (MRI) scan of the person's brain showing lesions (areas of demyelination in the central nervous system).

It is now more and more possible to be diagnosed as having ‘definite’ MS on a first visit to a neurologist, but it is also quite likely that the diagnosis will be uncertain, and that the person will be referred for further tests.

Read more in MS in focus - Is it MS?