Relapses have a definite definition. But, we all have to learn for our own disease what is a true relapse and what is part of the normal ups and downs of our symptoms. For example overdoing activity or getting overheated will cause our symptoms to be way worse for some time (a day or so) afterward. Also we all notice that our cognitive problems are worse sometimes and better sometimes.
Here is one set of definitions about what relapses and remissions are and how you look at them.
Basically anything new is report-worthy to the doc. Also, any current or old symptom that is suddenly much worse than it ever was - or is there but changing - should be reported. Also, different neuros want to hear about different things. I gave you what my neuro wants. You need to ask your neuro for his guidelines. But, anything new and major needs to be reported. (I wouldn't report a new tiny area of paresthesia, for example)
http://www.medhelp.org/health_pages/Multiple-Sclerosis/Relapses--Pseudo-Relapses-and-Remissions/show/372?cid=36
Also, when the effect of the steroids wears off, (3 weeks or so) there may be a return of some symptoms' severity). The steroids are not a cure, just temporary reducers of the inflammation. Sometimes the inflammation just dies on down and the relief is long-lasting, but sometimes it ramps back up.
I hope this helps.
Quix