Preventing a concussion is important … but making sure it doesn't happen a second time is essential.

Concussions temporarily change the way a brain works, according to John Lucas, MD, of Spartanburg Regional's Sports Medicine Institute.

“If you're experiencing the symptoms of a concussion and you take another hit to the head, your symptoms can get dramatically worse,” Dr. Lucas said.

During this segment of Discover Health, Dr. Lucas describes worst-case scenarios and how concussions are treated.