Post-polio syndrome refers to a cluster of potentially disabling signs and symptoms that appear decades — an average of 30 to 40 years — after the initial polio illness.
Polio was once one of the most feared diseases in America, responsible for paralysis and death. Shortly after polio reached its peak in the early 1950s, the inactivated polio vaccine was introduced and greatly reduced polio's spread.
Today, few people in developed countries get paralytic polio, thanks to the polio vaccine. According to some studies, however, up to almost half the people who had polio at a young age may experience certain effects of the disease many years later — post-polio syndrome.