A recent study found that 85% of concussions go undiagnosed. Another study found that nearly 63 percent of varsity soccer players had symptoms of a concussion at some point, but only about 19 percent actually knew it. The reason this can happen is because you do not have to lose consciousness to have a concussion, so most players will experience a blow to the head and get right back into the game. However, repeated blows to the head can accumulate and cause just as much damag