There are four recognised types of MS and all have a different effect, these are as follows:
Relapsing and Remitting - Here someone will have a "relapse" where symptoms appear and then fade away, either partially or completely (remission).
Benign – This is where someone has a relapse and then for about 10 or 20 years they show no further signs.
Secondary Progressive – Most people who have relapsing and remitting go on to develop this; approx 65%. This is as it states is progressive in it's nature, but with changes taking place a over a long time, it may not be noticed.
Primary Progressive – This effects approx 10 to 15% of MS sufferers. Once again it is as the name suggests, however with this the progression the condition gradually gets worse over time, rather than any relapses. It is probably the most aggresive form of MS.
Here are graphs that go someway to describing the impact of the different types of MS: