Relapse Relapses suck. A lot. A relapse (aka an exacerbation or flare up) is anything that either gives you new symptoms or brings back old ones. They are different for everyone, unique in the same way snowflakes are. If snowflakes sucked. Other Terms PML A rare virus linked to MS involving progressive brain damage. Primary Progressive MS Worsening symptoms from the get-go, with no relapses or remission. Progressive-Relapsing MS A rare kind of MS affecting just 5% of the population. QoL (Quality of Life) A phrase you might hear from your medical team. View More