Increased understanding of concussions' long-term dangers has made football a more uncomfortable sport to watch; seeing Patriots running back Stevan Ridley seemingly knocked unconscious during the AFC championship game was upsetting in a way that it wouldn't have been 10 years ago. News-conscious football fans might have started noticing concussions in another context as well: fictional adventure stories. Heroes are always getting slugged in the head in the middle of tense situations and waking up somewhere perilous — the blackout is a convenient device for wrapping up one scene and starting another without any break in the action. And wizard icon Harry Potter suffers such injuries at a frequency that's unusual even for his brand of dashing, courageous protagonist.
The good news is that fiction isn't real, so we don't have to worry about Harry fighting depression, memory loss, and early-onset dementia. But it does seem likely that characters casually and quickly recovering from repeated, forceful blows to the head will become a distractingly implausible anachronism for future readers of J. K. Rowling's series, not to mention fans of countless other spies and detectives. (Perhaps a return to the days of frequent chloroforming is in order.) Here, a review of all the brain trauma Harry suffers.
Note: The Mayo Clinic defines a concussion as any blow or violent shaking of the head "that alters the way your brain functions." Seeing stars? Feeling woozy? Needing a few minutes to collect your thoughts? They're all a form of concussion, and they're particularly bad for pre-adults.
The Sorcerer's Stone
— Battling his murderous teacher Quirrell, Harry is flung through the air and falls "into blackness," presumably after smashing into the floor or the wall. He wakes up three days later.
The Chamber of Secrets
— Harry and Ron crash Mr. Weasley's flying Ford Anglia into the Whomping Willow: "With an earsplitting bang of metal on wood, they hit the thick tree trunk and dropped to the ground with a heavy jolt ... a golf-ball-sized lump was throbbing on Harry's head where he had hit the windshield."
The Prisoner of Azkaban
— Harry passes out during a Quidditch match when Dementors approach, falling from his broomstick and waking up in the hospital wing later to overhear people saying things like, "I thought he was dead for sure."
The Order of the Phoenix
— Startled while hiding in a flower bed outside the Dursleys' house, Harry cracks his head against a window sill: "Harry felt as if his head had been split in two; eyes streaming, he swayed, trying to focus on the street and spot the source of the noise."
— Just a few moments later, Dudley Dursley punches Harry in the side of the head: "Small white lights popped in front of Harry's eyes; for the second time in an hour he felt as though his head had been cleaved in two."
— Practicing Occlumency lessons with Snape, Harry blacks out, then finds himself lying on the floor after he regains consciousness. "There was a lump on the back of his head from where he had hit the ground and he felt feverish."
(In addition to the times he's actually injured, Harry demonstrates concussion-like symptoms throughout Phoenix. He's grown accustomed to his scar hurting when his mind connects to Voldemort, but in this book, routinely finds his head "throbbing fit to burst ... beginning to ache ... pounding" even when no telepathic link to the Dark Lord has been established.)
The Half-Blood Prince
— Hiding in the Slytherin compartment on the train to Hogwarts, "Harry ... did not notice Goyle reaching up for his trunk; as he swung it down, it hit Harry hard on the side of the head. He let out an involuntary gasp of pain ... eyes still watering and head still throbbing ... he toppled out of the luggage rack and fell, with an agonizing, floor-shaking crash at Malfoy's feet ... [Malfoy] stamped hard on Harry's face. Harry felt his nose break; blood spurted everywhere."
— During Quidditch tryouts, one Gryffindor "managed to raise a lump the size of an egg on the back of Harry's heard with a ferociously hit Bludger."
— Ron's replacement as goalkeeper, McLaggen, mishits a Bludger into Harry's face, cracking Harry's skull and knocking him out for hours. C'mon, McLaggen!
— Snape gets the best of Harry in a duel: "[Harry] fell forward, his face smacking the ground, blood pouring out of both nostrils ... Harry felt a white-hot, whiplike something hit him across the face and was slammed backward into the ground. Spots of light burst in front of his eyes."
The Deathly Hallows
— Traveling on a flying motorcycle piloted by Hagrid, Harry is ambushed by Voldemort and falls from the sky, slamming hard into a muddy yard, knocking out some teeth, bloodying up his head and face, and knocking him unconscious.
— Remus Lupin sends a spell at Harry that slams him into a wall. "He could feel a lump swelling where his head had hit the wall."
— Battling Death Eaters inside Hogwarts Castle, a terrible explosion knocks Harry to the ground and covers him in debris. Disoriented and confused, he realizes the explosion has killed Fred Weasley.
The Tally: 7 books, 13 concussions, 4 of them severe, all before the age of 18. Hope he can still get coverage under the Hogwarts insurance plan.