It's a widespread beliefnote that stress causes hair to turn gray just ask your grandmother. Stress, however, comes in many forms, and some are more effective than others at turning hair white.
One of the most effective ways to turn a character's hair completely white would be the stress of prolonged illness. There may be some Truth in Television to this, but typically it's taken to extremes. In some cases, this trope is used to justify the white-hair part of White Hair, Black Heart if he happens to also be an ill guy.
Note that this trope also applies to people whose hair has turned white due to prolonged stresses similar to diseases, such as being a prisoner of war. If a character's hair suddenly changes color forever due to supernatural causes, it's Locked into Strangeness. If this is a direct (often temporary) effect of supernatural influence, it's Power Dyes Your Hair. Also has no relation (usually) to Brain Bleach.
Also note that in Real Life hair already grown can't turn white (unless you bleach it artificially). Grown hair consists of dead cells, which can't change their color. But don't expect fiction to care.
Subtrope of Prematurely Grey-Haired.
- Fist of the North Star
- Toki is shown to have black hair in pre-war flashbacks and indeed, his hair turned white due to the same radiation poisoning that is slowly killing him.
- When Rei gets hit by an attack from Raoh that would kill him in three days, he enlists Toki's aid to give him one extra day to live so he can defeat Juda. The procedure is so excruciatingly painful that after it is complete, his hair changes from blue to stark white.
- Bleach: At the age of three, Captain Ukitake was diagnosed with a fatal lung condition that is implied to be tuberculosis. The shock and stress of the diagnosis turned his hair white over a span of three days. When his parents seek a divine miracle, Mimihagi merges with Ukitake's lungs, sustaining his life without curing him in return for a hiding place until the day Yhwach destroys the Soul King. On that day, Ukitake sacrifices his life by releasing Mimihagi to save Soul Society.
- Half of Dr. Black Jack's hair started coming in white after a land mine blasted his head apart when he was a child.
- In One Piece, Hody Jones and his crew had their hair turn white after overdosing on energy steroids, giving them a large power boost, but shortening their lifespans.
- In ½ Prince, Long Dian's hair has turned white, apparently due to his life-threatening disease. He regains black hair when he gets a synthetic body.
- In Hunter × Hunter, Knov's black hair turns to white after sensing Shaiapouf's En and suffering a mental breakdown during his infiltration op.
- JoJo's Bizarre Adventure:
- From Your Lie in April, though not really turned into white, Kaori's hair color become much lighter shade of blonde after she was hospitalized in episode 13. In fact her skin and eyes become paler as well. Her eyes go from a crisp blue to a dull grey.
- In Naruto, this happens to Nagato when he uses the Outer Path - Samsara of Heavenly Life Technique to bring Back from the Dead everyone he killed when he invaded Konoha: the strain causes his hair to go white before he dies. Kabuto later revives him with Impure World Reincarnation, and Nagato's hair is still white, that is until he absorbs some of Killer B's chakra, causing his hair to turn red again.
- Tokyo Ghoul: After enduring ten days of Cold-Blooded Torture at the hands of Yamori, Kaneki's hair turns white from the trauma.
- In the second Gintama movie, Be Forever Yorozuya, there is an outbreak of a disease called the White Plague, and one of the symptoms is that the hair goes white. This happens to Shimura Otae, who is implied to have died before the timeline reset. Also, Sakata Gintoki, whose hair is normally silver, turns completely white due to being the host of this disease.
- Rurouni Kenshin: It's implied that watching Tomoe die is what caused Enishi's hair to go white over a very short period of time when he was a mere boy.
- The title character of XIII has a grey streak on his left temple where a bullet scratched him pre-amnesia.
- Beasts of Burden: In "Grave Happenings", the black dog Digger has a horrific supernatural encounter that leaves him in shock and turns the fur on his face white.
- Cleo of Wetmoon has her hair fall out and once it regrows it's white.
- Fatal Frame VI: Vengeance: Rina Oshiro was so traumatized by the events she witnessed at the Watanabe Shrine, which led to the deaths of her friends and twin sister, that her hair turned white at age 18.
- Subverted in My Sister Leni. When 1-month old Lincoln's hair started paling, his parents understandably freaked out and went to the doctors. Tests found nothing wrong with Lincoln. His hair just turned white for no apparent reason.
- This happens to Johnathan Harker in Bram Stoker's Dracula as his hair turns grey when he returns to London and then white as he aids in fighting the count.
- The villain of the Saw franchise for the first three films has white hair at a relatively young age (canonically in his mid-forties during Saw III) due to being terminally ill with cancer.
- The vampiric disease in The Omega Man turns people's hair white instantly (as we see when Lisa gets infected). And curing it turns their hair back to a normal color instantly. Somewhere a Virologist Is Crying.
- Brought up during Lincoln, as Grant notes the physical toll the war has taken on Abe.
Grant: By outward appearance, you're 10 years older than you were a year ago.
Lincoln: Some weariness has bit at my bones...
- It: Henry Bowers's brown hair turns white and he is driven insane after seeing IT's true form.
- The Dresden Files:
- We see that Lea has white streaks in her hair after prolonged imprisonment by the Winter Queen in order to "cure" her insanity/ambition.
- Justine's hair turned white after an intense feeding session with Thomas nearly killed her. She recovered much of her physical health in the years after, but her hair has remained white.
- Percy Jackson and the Titan's Curse gives Annabeth and Percy cute little matching gray streaks from the stress of holding up the sky. Though oddly enough, they're never brought up again afterwards. They're brought up in Mark of Athena (The Heroes of Olympus) and it's said they disappeared after some time.
- In Dean Koontz's Dragon Tears, Harry Lyon's former partner Ricky Esteban had to retire from the police force on medical grounds after being gut-shot, subsequently losing a big chunk of his digestive system. His hair went white and he seems prematurely aged in other ways, not surprisingly.
- A Song of Ice and Fire:
- Lancel Lannister's near-mortal wound and long recovery are said to have changed his fine blond hair to a brittle white mess.
- In A Dance with Dragons, Theon's hair turns white as a result of the malnutrition and torture he suffers from Ramsay.
- In Bram Stoker's Dracula, Jonathan's hair begins to go grey after his imprisonment at the Count's castle. It's believed by some to be another way in which he grows to mirror Dracula himself, similar to his personality change and growing fixation on his weapons. Of course, this gets even more patently ridiculous later on: after Mina explains all the deprivations the Count has been secretly putting her through and the fact that he's setting her up to become another vampire thrall, Jonathan's hair is explicitly stated as going stark white right then and there, grown hair and all.
- Les Misérables: Fantine's hair turns prematurely white after she sells most of it to provide money for her daughter and then contracts tuberculosis.
- Jem in The Infernal Devices series. Turns out it's because of a demonic hallucinogenic drug originally used to torture him as a child. Same goes for his eyes.
- The Witcher: The strain of the often lethal Trial of Grass left young Geralt with white hair and unnaturally pale skin.
- Kit Smith's hair is noted as prematurely grey (he's only around thirty when he is introduced in Aunt Dimity's Christmas); he spent years living as a vagrant and nearly died of a combination of hypothermia and pneumonia.
- Nile Barrabas, the mercenary hero of the 1980s Gold Eagle Heroes "R" Us series Soldiers of Barrabas, had his hair turn white after a head injury in the Vietnam War. This gives him a startling appearance that's often lampshaded.
- In Kiki Strike, a childhood illness is said to have caused the titular Kiki to have platinum blonde hair.
- Doctor Who: In "The End of Time", the Master's hair turns white following a sabotaged resurrection. He happens to be slowly dying, exacerbated by Cast from Lifespan superpowers that his Horror Hunger cannot entirely deal with.
- On iZombie, one of the first signs of someone becoming a zombie is their hair turning white, followed by their skin.
- Kamen Rider Ex-Aid: Unlicensed doctor Taiga Hanaya has Skunk Stripes as homage to Black Jack. They came about as a side effect of losing his carreer, friends, sense of self-wroth and nearly sanity because of Zero Day. The prequel mini-series, Episode Zero, show how he changed from caring radiologist to arrogant, angry Back-Alley Doctor he is known as in the main story..
- Happens all the time in Stargate Atlantis whenever someone becomes a victim of Wraith feeding. There are a few occasions where it is reversed by the Wraith returning the nutrients it stole, but those are rare special occasions.
- In Hamilton, Hamilton's hair is said by the ensemble in "It's Quiet Uptown" to have "gone grey" after the death of his son.
- Lau Chan from Virtua Fighter, after having black hair most of the series, goes white and visibly ages as his Incurable Cough of Death gets worse by the fifth game.
- This is one of the fan theories regarding Fenris's silvery hair in Dragon Age II; he canonically underwent an agonizing experiment that wiped his memory.
- In Resident Evil 5 Jill's hair turns platinum blonde, almost white, after being experimented on by Wesker.
- Fire Emblem: Three Houses has this a sign of someone who underwent the very painful, very dangerous, and never willing process of being implanted with a second crest. Edelgard and Lysithea do not naturally have white hair.
- In Phoenix Wright: Ace Attorney, Godot's hair turned white after he fell into a coma after being poisoned.
- In Super Danganronpa 2, Nagito Komaeda's hair is white, and it's implied that this is due to the illnesses he's had as a result of his constant good and bad luck.
- In Umineko: When They Cry, Tooya Hachijō (aka Battler Ushiromiya)'s hair apparently turned white after they nearly drowned and had a traffic accident. This also results in a close resemblance to Kinzo Ushiromiya, the family patriarch, who also had white hair in his youth.
- In The Order of the Stick, Ian Starshine's red hair turned white after three years of malnutrition in the Empire of Blood's jails.
- This happens to Angelique in Kevin & Kell after the main characters kidnap her and terrorize her for a night in retaliation for flooding the meat market with rabbit meat. Considering Angelique's secretly a rabbit as well, and therefore sold out her own species, this reads more as Laser-Guided Karma.
- Could possibly be used as Trope Namers : Marie Antoinette Syndrome
- Truth in Television, to some degree. People suffering from severe and sustained malnutrition, such as some prisoners of war, can have their hair turn blond over time. This has even happened to an elderly man held prisoner by guerillas, whose hair turned blond from its previous grey. However, it turned back once he was rescued and back on a proper diet.
- While not always resulting in lighter hair, patients undergoing treatments such as chemotherapy sometimes find that their hair grows back a completely different color or texture.
- While not exactly a disease, high amounts of stress over an extended period of time tends to significantly speed up the aging process, as any before-and-after pic of an American president would tell you.