How is multiple sclerosis (MS) diagnosed?

Multiple sclerosis (MS) is a complex and unpredictable disease. There is no single blood test, symptom, or physical finding which can definitely diagnose a person with the disease. Some early signs or symptoms of multiple sclerosis can also be caused by other diseases.

A diagnosis must be made by going through a careful process, making sure the findings are consistent with multiple sclerosis and ruling out other causes.

What should I do if I think I have multiple sclerosis?

If you're concerned you have multiple sclerosis symptoms please see your GP in the first instance. They may refer you to a Neurologist if they believe further tests are necessary. Remember, you can seek support from health professionals before, during and after a diagnosis.

Criteria for a MS diagnosis

There can be many reasons your body is showing the first signs associated with MS. However, there are ways to confirm if those signs actually lead to a diagnosis.

While there is no exact formula, the basic "rule" for a diagnosis has two criteria:

  1. There must have been two attacks at least one month apart. An attack, also known as an exacerbation, flare, or relapse, is a sudden appearance or worsening of one or more multiple sclerosis symptoms, lasting at least 24 hours.
  2. There must be more than one area of damage to the sheath that protects your nerves, called myelin. These are the scars or ‘sclerosis’ caused by the disease. The damage to myelin must have occurred at more than one point in time.  It’s also important to ensure the damage hasn’t been caused by another disease.

MRI (magnetic resonance imaging)

MRI is the preferred method used to detect lesions (also known as scarring or damage) caused by multiple sclerosis in the central nervous system (made up of the brain, the optic nerves and the spinal cord).

A multiple sclerosis diagnosis may not always be made solely on the basis of MRI.

There are other diseases that cause lesions in the central nervous system that look like those caused by multiple sclerosis. There are also lesions found in healthy people, particularly in older people, that are not related to any ongoing disease.

A normal MRI doesn’t absolutely rule out multiple sclerosis either. Sometimes your medical history and the results of other clinical testing can indicate multiple sclerosis. There are many factors that create a clear diagnosis.

Clinical examination

Other symptoms of multiple sclerosis are evaluated during a clinical exam from a physician. This covers an extensive review of mental, emotional and language functions, movement and coordination, vision, balance and the functions of the five senses. The person’s history is also taken into consideration.

Sometimes other tests are needed

It’s not usually necessary to do all diagnostic tests for every person. Sometimes if a clear-cut diagnosis can’t be made based on MRI and clinical exams, additional tests may be ordered. These include:

  • electrical diagnostic studies which can show if there is a slowing of messages in the various parts of the brain
  • cerebrospinal fluid studies which test for the presence of oligoclonal bands, indicating an abnormal autoimmune response (these are present in other diseases as well so they can’t be used as positive proof of multiple sclerosis)
  • blood tests which may rule out other causes for various neurological symptoms.
If you think you’re showing first or early signs of MS, take the first step and see your GP today. We have many resources and support systems in place to help you through the entire process. Feel free to call our friendly team on 1800 042 138 for advice.

Learn more

Find support in your local area

Find information, support and services in your local area – whether you’re a person living with multiple sclerosis, or a family member, friend or carer.

Newly Diagnosed

A multiple sclerosis diagnosis can be extremely difficult to come to grips with. All of a sudden there is a lot of new information to absorb, questions to ask and key decisions to make. We're here for you - from the day you're diagnosed and each day after.


Dig deeper with a wealth of publications on a wealth of topics including symptom management, wellness, disease information, booklets for family and carers and more.

Call Us - 1800 042 138

MS Connect is our free telephone and email information support and referral service.

Register with MS

By registering with MS you can access our full range of services and support.

Stay informed with the latest from MS


Connect with us...

Multiple Sclerosis Limited, ABN 66 004 942 287