Self-Abuse

Masturbation portrayed as being bad for you, possibly making you go blind, go deaf, or grow hair on your palms.

Another supposed result of masturbation was that it would make you go mad, though there was at least some reason for thinking this; asylum doctors would notice that many mentally disturbed people masturbated a lot, and reasonably (though incorrectly,) concluded that the madness was caused by masturbation.

Mostly a Discredited Trope we have outgrown. While certain Jewish and Christian groups still do frown on male masturbation because of the story of Onan in the Old Testament, the idea that masturbation could cause actual, physical harm came from Victorian Britain and the Second Great Awakening in the US. These were the days of Moral Guardians like U.S. postmaster Anthony Comstock and Boy Scouts founder Lord Baden-Powell, who believed that children indulging in "Secret Practices" would waste away their youth and vigor, and scores of ministers whose most lasting innovations in hygiene turned out to be Graham crackers and Kellogg's Corn Flakes.

The bitter irony? All those old wives' tales and warnings have been turned on their ear in recent years, particularly for male masturbation. Separate studies in 2003, 2004 and 2006 suggested that men who ejaculate regularly have a reduced risk of prostate cancer. The theory is that keeping the stores of seminal components from getting stale clears out carcinogenic impurities.

Not to be confused with Self Harm.

Anime and Manga

 * In the hentai manga Bust to Bust, one of the girls is enough of a nymphomaniac that she can't stop diddling herself when her boyfriend isn't around. She's also kinda crazy, which leads him to claim "I guess masturbation really does melt your brain. Better not report this to any scientific institutions..."

Film
"Jim: Maybe Stifler can be nice, and nothing will go wrong.
 * In Police Academy 2, the disgruntled prankster recruit Mahoney swaps the overbearing man in charge of recruit training's shampoo with fast-curing helmet repair epoxy. This has the desired effect of Supergluing the victim's hands to his head. When he finally manages to get his hands free, they are naturally covered with hair. When he asks a group of recruits if anyone can explain how this happened, Mahoney replies, "I can, sir. And if you don't stop, you'll go blind."
 * Avatar includes Dr. Augustine's blink-and-you'll-miss-it line as Jake is examining his new body's neural queue (in his hair, as a ponytail): "Don't play with that, you'll go blind."
 * In Pirates of the Caribbean: Dead Man's Chest, when the other crew members see the hairy black spot on Jack's hand (the mark of a curse), he's quick to say that his eyesight's as good as ever.
 * In Full Metal Jacket, a story is told relating how one marine was going to be discharged on a Section 8 for his uncontrollable urge to masturbate, even in public. His nickname? Hand Job.
 * In Saint Ralph, the characters literally refer to it as "self abuse," a reflection of the 1950's Catholic school setting. However, since the title character is 14, the concept that it's bad for him does not stop him.
 * Another Catholic school movie, Heaven Help Us, features a compulsive masturbator who's also pallid, twitchy and socially awkward.
 * Referenced in American Wedding.

Michelle: ...aw, sweetie. You've gotta stop masturbating. It's melting your brain."


 * In The Love Guru, the protagonist is told by his severely crosseyed teacher that if he masturbates, it will make him crosseyed.

Literature
""...Say, what's the matter with you lately, anyways? You're always tired and I never see you at gym and you've got terrible circles under your eyes. You're not doing anything at night are you?"
 * Dracula is stated to have hair on his palms in the original novel, something commonly believed to be a side effect of masturbation until recently.
 * Doctor Crombie, eponymous character in Graham Greene's short story, expounds that cancer is a result of masturbation... More accurately, he claims it is a cause of "playing with oneself", the euphemism giving rise to humour. The central theme of the story is to demonstrate the folly of conflating correlation and causation: "Almost one hundred per cent of those who died of cancer had practised sex".
 * This is discussed in the memoirs of the real-life Casanova when he makes friends with a Turkish Muslim and they compare attitudes toward sex in their respective religions/cultures. Casanova subscribes to the view that too much masturbation will make you sickly and weak (of course, his solution is to deal with horniness by sleeping with everything that moves and relying on the sacrament of confession to keep you out of hell) while Yusuf says that obviously "too much" of anything is bad by definition, but there's nothing wrong with masturbation per se, and that anyway it's a completely unenforceable rule. They also talk about male vs. female masturbation, with Casanova saying that girls don't run the same risk as boys because they're not losing a bodily fluid every time they do it.
 * Used sarcastically in Auntie Mame when Patrick's roommate gets suspicious (what he's really doing at night is sneaking out to help Mame with a Zany Scheme she's suckered him into):

I gulped. "Well, gosh, Junior..." Then I saw what he meant. "Yeah, sure I am, Junior. Six or seven times a night. It'll drive me crazy and no nice girl will marry me and all my kids will be idiots. Be sure to tell your old man that for me next time you write." I snatched up my towel and stalked off to the showers."

Live Action TV
"Graeme: Now, I've left this one alone for six months to prepare him for the isolation. Let's see what he's--don't do that!
 * Played With in an episode of Supernatural. Sam and Dean wind up in a town where all the old wives tales - like "your face will stick that way" - actually come true, and Dean realises it's affecting them when he ends up with hairy palms. Sam is not amused.
 * Mystery Science Theater 3000, "Body Care and Grooming": "And remember, when you touch yourself, the saints cry. Good night."
 * On Mad Men, a ten- or eleven-year-old Sally experimentally masturbates to The Man From UNCLE while staying over at a friend's house. The friend's mother catches her, freaks out, takes her home, and tells her mother, who threatens to cut off her fingers if she ever does that again.
 * In an episode of The Goodies, Graeme is training rabbits in preparation of sending them into space.

Tim: (laughing) He probably can't hear you.

Graeme: ...Pardon?

Tim: ...Oh, I'm so sorry."

Music
""Oh Mrs Palm and your five lovely daughters
 * "I'm a Wanker" by Ivor Biggun:

thank you for having me and being oh so kind!

I've got pains in my arms and my dong is getting shorter

my knees have turned to water and I think I'm going blind.""

Radio
"Denis: What is it? I was--don't do that, Don, you'll go deaf!
 * In England, a common rumor is that it causes deafness. In a Christmas episode of Hello Cheeky, it's mentioned that Denis King and his trio spend the winter hibernating under the couch with a copy of Playboy. Thus:

John: He can't hear you, Denis.

Denis: ...What?

John: ...Right."

Video Games

 * Lunar Silver Star Story Complete for the PS 1 had a part where the lights go out and leave the party blind. Kyle says "I can't see! I'm blind! But I thought that was only a myth!" to which Nall replies "What do you mean? The cave went dark!" Jessica says "Trust me, Nall, you DON'T want to know what he's talking about."

Web Original

 * Bakura in Yu-Gi-Oh the Abridged Series gets afflicted with "the deadliest of all British diseases": Wanker's Cramp.
 * In the closing credits of that episode we get the sage advice "Avoid Wanker's Cramp! Know your limits!"

Jokes

 * There are plenty of jokes about how parents will lecture their children about masturbation and its negative consequences. One gem we heard a lot in school was about a dad who tells his son to stop masturbating or he will go blind... and his son then tells him that he is looking in the wrong direction and that he is standing over here, implying that the dad can't see well as a result of him masturbating too.
 * Variations on the theme of "Masturbating'll make you go blind, you know!" "Who said that?" and "Masturbation'll go make you go deaf!" "What? Speak up!" are always popular in junior high.

Western Animation

 * One episode of American Dad features Stan showing his son, Steve, an admittedly hilarious anti-masturbation propaganda film that ends with a boy screaming "NOOOOO!" as he's growing hair on his palms and his eyes melting out. The kid turns up (in a deleted scene) later in Stan's head and says something along the lines of "It was worth it."