What is a Relapse?

A relapse is defined as the appearance of new symptoms, or the aggravation of old ones, that last at least 24 hours (more often a few days or weeks) and is associated with inflammation and demyelination in the brain or spinal cord.

Thus the symptoms you experience during a relapse are due to disease activity in the central nervous system.

It is important to remember that the episode needs to last for at least a day to be considered a relapse. This is because MS symptoms can often return for short periods of time (minutes or hours) for a variety of reasons including exercising in a hot environment, when you have a fever due to a virus or other infection, when you're tired or when the weather is hot or humid; this is not a relapse but an exacerbation of your MS. So if you do experience an exacerbation of your MS symptoms think about what else could be contributing to it; have you been overtired or stressed? Have you got a sore throat or viral illness?

Of course you should seek medical advice if the symptoms are of significant concern and impact such as loss of power or strength in your arms or legs or visual loss.

The MS Society nurses can chat with you and give you advice if you are concerned or you can visit your GP. If symptoms persist and it appears to be a relapse you should be seen by your neurologist.