Victorian Novel Disease

Romantic opera usually deals with the subject of some romance which never comes off owing to the untimely demise of the prima donna through one of four causes: murder, suicide, madness or TB.

—Anna Russell

If you're the star of a Victorian Novel, you're preferably blonde and blue-eyed, with an alabaster brow and feet light as the entrance of Spring. So pure are your thoughts that you faint at even the sight of blood, and have little stomach for gory tales.

You're also dying, probably of "consumption", which fortunately has no ill effects other than adding a poignant cough to the appropriate sentences, and making your eyes even brighter, your skin even paler, and your complexion even more striking (what was actually called "consumption" in the Victorian era is known as tuberculosis today, and its real-life effects are not nearly as glamorous as Victorian Novel Disease makes them out to be).

Standards of beauty are a funny thing. When the lower class is poor and thin and haggard looking, the nobility commissions portraits depicting themselves as Rubenesque, with rosy cheeks and dimpled arms, to show off their indulgent dining habits as a way of immortalizing their wealth. However, when the economy stabilizes and the poor are able to be plump and rosy-cheeked, then the standard of beauty... shrinks. Women become diminutive, frail, wan little things, prone to Fainting spells and headaches. (Rather like Dr. Seuss's star-bellied Sneetches.)

In its final stages, this develops into all the symptoms of being an Ill Girl - being Always Female, dying of some disease that is very slow at actually making you waste away, and poignant musings on death, culminating in a tragic death scene. The very most telling symptom is when people around you start saying you are Too Good for This Sinful Earth.

In modern times, a virulent strain has developed as the Soap Opera Disease.

The Littlest Cancer Patient is usually more upbeat about their impending death.

Not to be confused with Conspicuous Consumption.

Examples of Victorian Novel Disease include:

Anime and Manga

Parodied and subverted in Count Cain, wherein several vain girls are tricked into ingesting various parasites to get that lovely white pallor.
Rin's mother in Kodomo no Jikan. Though they actually stated she had lung cancer, the way her illness is treated reeks of this trope.

Film

Moulin Rouge and Satine's illness, also based off of The Lady of the Camellias.
In Sherlock Holmes: A Game of Shadows, Irene dies from "a rare form of tuberculosis", due to Moriarty poisoning her tea.

Literature

As the above quote declares, Marguerite aka The Lady of the Camellias (from the novel by Alexandre Dumas fils) is dying of a Victorian Novel Disease. Because nothing, not even the deterioration of one's lungs, should stand in the way of one's career as a successful courtesan!
In Anne of the Island, Anne's childhood playmate Ruby Gillis is revealed to be dying of "galloping consumption" (acute tuberculosis of the lungs). May be considered a play on this, as in childhood Ruby, instead of fainting gracefully at the scene of a drama, would usually just go into hysterics. However, it's still a Tear Jerker. Especially since Ruby, having been rather shallow all her life, is terrified to die and leave everything she's always considered important behind her. While she says she "doesn't doubt but that she'll go to Heaven", she's afraid because frivolity is all she's ever known, and now she's facing the unknown rather unprepared for it.
This trope is also known as "Dickens Syndrome" due to its overuse in said author's novels, usually coupled with Too Good for This Sinful Earth.
Agatha Christie describes in her autobiography how her elderly grandmother tried to make Agatha seem more interesting to suitors by speaking of how frail and sickly she was. This resulted in the suitors (being 20th century boys) becoming very concerned, and Agatha very annoyed, since she was as healthy as anything.
A gender-flipped example in Wuthering Heights where it is Edgar who dies of a wasting illness. Although, admittedly, the former was complicated by a particularly poisonous Tragic Dream and a Miser Advisor, while the latter was increasingly convinced that his wife was having an affair.
In Boris Vian's L'écume des jours, Chloé dies from a water lily growing in her lungs (yes, it's a weird novel), the effects of which, besides a cough, are largely to make her beautifully pale and languid.
Evangeline "Little Eva" St. Clare from Uncle Tom's Cabin.
Sherlock Holmes contains a notable subversion. Evidently, the only thing more wringing than the plot development where someone turns out to have consumption is the plot development where it turns out no one has consumption.
In one Doctor Who Eighth Doctor Adventures novel, Camera Obscura, the Doctor and his companions visit the Victorian era, and the Doctor is a bit under the weather and is recovering from having a sandbag dropped on him, and consequently his lungs crushed flat and his heart punctured by his broken ribs. He gets into a fight, goes ash-white and faints, and is suspected of having consumption. Note that he's kind of a prettyboy and his usual costume is a bottle-green frock coat, a cravat, a double-breasted waistcoat, etc., so it doesn't take much to make him look like a consumptive Victorian poet, which may have some connection to the fact he generally swoons an awful lot.
Arthur Dimmesdale? From The Scarlet Letter? Then again he actually dies.
Parodied, or Played for Drama, in Dracula, depending on how you read the novel. In classic literature, tuberculosis was used as a stock disease. It was rarely referred to by name, but the symptoms were always the same: a young lady would become pale and sleepy, and a blush would show on her sickly face. When Van Helsing refuses to name Lucy's illness, the reader of the era would have assumed that she has tuberculosis. But actually, Van Helsing realizes that she's becoming a vampire.
A Tree Grows in Brooklyn has three consumptives: Johnny's brother Andy, neighbor Henny Gaddis, and Sergeant McShane's wife, Molly. Henny is the only one Francie actually meets, and she can't believe he's dying because he has such bright eyes and rosy cheeks.
In Lois McMaster Bujold's Komarr, Ekaterin mentions that when girls pretend it's the Time of Isolation, they always leave out all the bits about dying in childbirth, or of dysentery, and if they're every dying romantically of a disease, "it's always an illness that makes you interestingly pale and everyone sorry and doesn't involve losing bowel control."
Lady Pole in Jonathan Strange & Mr Norrell. Quite a few people were seriously worried about her health but her mother refused to hear a word of it.
In the original story of A Christmas Carol, the cause of Dead Little Sister Fan's death isn't explained, but in the 1951 Alistair Sim film, she is told and shown to have died in childbirth, which also happened to Scrooge's mother in the backstory of this version.
This is precisely what Ill Boy Peter dies of in the treacly 1982 Elisabeth Kubler-Ross novel Remember The Secret. He's even taken to heaven by angels.
In Crime and Punishment, Katerina Ivanovna dies of consumption after Marmeladov's funeral.
In Susann Cokal's Breath and Bones, Famke suffers from TB in a curious way - she coughs a lot, then coughs blood a lot, then gets treatment, and then it eventually returns...though it is not what actually kills her in the end.
Averted in Anthony Trollope's 47 novels in which the heroine is generally quite healthy and suffers only in agonizing over the choice of a beau. To be fair, however, Trollope wrote mostly about the middle classes while Dickens wrote mostly about the lower classes.
- Trollope doesn't avoid death, it's just that his characters die realistically and unsentimentally - when they die on stage.
In Jorge Isaac's María, this is the demise of the titular character.

Live Action Television

The BBC writers inserted examples into Lark Rise to Candleford. The Post Office inspector takes sick after storming out of the post office having caught Dorcas in the act of providing Irish labourers with out-of-hours service. He faints, falls off his horse and is rescued, brought into the post office in a delirium burbling about his lost love Helena (or Eleanor, it's not clear which). A similar thing happens with Thomas Brown, played for laughs, when he falls off his bicycle in high dudgeon over Miss Ellison's treatment of her brother, and Cabbage Patterson's wife takes to her bed and allows the constable to woo Pearl Pratt. None of these episodes are in the original book.
Mitchell and Webbs "The Man Who Had A Cough And It's Just A Cough And He's Fine.", a film by the same director as "Sometimes fires go out."
House: "It's never lupus."
- Except that one time it was.

Opera

Verdi's opera La Traviata was loosely based on The Lady of the Camellias, so it's no surprise that lead female Violetta Valery suffers from this kind of thing.
Another operatic use of this trope is Mimi in La Boheme. She faints immediately after first entering Rodolfo's apartment; he sees her pale complexion and falls in love.
The operatic version of this trope was mocked by Anna Russell in "Anaemia's Death Scene."

Tabletop Games

A GURPS technology supplement for Steampunk campaigns has controlled inoculation with tuberculosis as a method for rich women to look suitably wan and feeble and hence, attractive. The Squick is intentional.

Webcomics

In Next Town Over, Markus thinks that Vane Black looks faint and pale and might have consumption. Given her previously revealed antics, this is improbable.

Western Animation

An episode of Drawn Together had Princess Clara contract "the consumption".

Real Life

The real Marie Duplessis died of tuberculosis, and her last two lovers stayed with her til the end.
It was considered fashionable and romantic for young women to seem sickly. To achieve this, many turned to morphine.