The development or progression of MS symptoms varies greatly from person to person, according to WebMD. For this reason, doctors use words like possibly and probably, because they cannot say for certain when particular symptoms will occur. Often, it takes years for a doctor to positively diagnose MS.
Most people who receive a MS diagnosis do so between the ages of 20 to 40, notes WebMD. During relapsing remitting MS, symptoms evolve over several days to weeks and can take months to recover from. Primary progressive MS is the most common type in people who develop MS after 40. This type causes a gradual progression of the disease. Progressive relapsing MS is least common, involving steady progression with acute attacks. Secondary progressive MS begins with relapsing and remitting and later evolves to progressive MS, sometimes months and sometimes years after initial symptoms.