Relapsing remitting (RRMS) is the most common type of MS, and it's the one for which there are drug treatments. There are also more in the pipeline. With this type of MS, a flare makes things worse, but things improve if not back to the level before the flare. This new level of disability lasts until another flare.
This cycle typically lasts for a while before a secondary progressive MS rears its head. During this phase, there are no more flares but rather a steady decline.
The steady decline can happen without the RRMS, and its referred to as primary progressive.
Note, these descriptions refer to the pattern of symptom progression, but it says nothing about the speed of disability accumulation. All of the drugs for slowing MS have been FDA approved for the first category mentioned. There are no drugs approved for treating progressive MS. While I've had MS for 7 years with no flares in the past 3 years, I have had increasing symptoms. Still, as I explained to my wife, I will not ask my neurologist if I am now progressive. Note, many men progress to progressive in first 5 years . From memory, it's close to half. I don't ask, because I don't want an answer which might give my insurance a reason to stop paying for treatments. When I say not FDA approved for treating progressive, that doesn't mean ineffective. So I stick with the most powerful drug on the market and hope.
My advice is research what you can to know to which questions you want answers and to which you are better not knowing. Send me a message if you have any questions or want a phone number of somebody who has lived and worked with MS for the past 7 years. Be calm. Most of us aren't in a vegitative state.