Figuring out if you are having an MS relapse can be tricky—whether you have just been diagnosed or have had MS for years. Your symptoms may not be a true relapse. You may be experiencing a pseudo-relapse instead. The good news is that the symptoms of a pseudo-relapse often resolve quickly. If symptoms resolve within a day, the episode was not a true relapse. And if symptoms have another cause, like an infection, proper treatment of this cause will resolve the symptoms.
Symptoms of a pseudo-relapse are not caused by new damage to the central nervous system. Pseudo-relapses may be caused by exposure to heat or infection. Symptoms caused by heat sensitivity are known as Uhthoff's phenomenon. Nerve damage from MS can make you very sensitive to even small rises in body temperature, such as from sunbathing, a hot bath, or a fever. If you experience new symptoms or exacerbated symptoms during or after increased activity, first rest and cool your body. If symptoms get better, then you were experiencing a pseudo-relapse, not a true relapse.
Mild infections, including viral upper respiratory infections (such as colds) and urinary tract infections, can also cause a pseudo-relapse. Once these infections pass, symptoms should get better. More severe infections, however, can cause a true relapse.
Medications, both for MS and for other conditions, can also cause new symptoms. Be sure to discuss any medications you are taking with your healthcare provider.