When you think of corsets, you probably think about those kooky Victorians and their tightlacing. You're not wrong, and we'll get to them in a bit. But the history of the corset goes back a lot further than that.
Try 2000 BCE, on the island of Crete, where a culture we've come to call the Minoans lived. Women in the Minoan culture wore clothing that was so similar to what was being worn in the 19th century (When their cities were first excavated) that some archeologists nicknamed one of the Minoan frescos La Parisienne, because the lady in the fresco would have looked right at home in fashionable Paris. The Minoan corset is depected as outerwear, as opposed to underwear, and is often shown with exposed breasts above (As opposed to many European corsets that covered the breasts, but more on that later…)
Perhaps the biggest oddity of the corset is that it vanished for 3000 years.
The next appearance it makes is when the word "corset" itself is coined in France, meaning "A lace bodice". In England, the corset was called a "stay".
But it really started in Italy. In the 1500s, Catherine de Medici brought it from Italy to France and being the super-popular fashion lady that she was it took off. These corsets flattened the bust and produced a sort of cone-shaped body with cleavage on
Later corsets created tube-like upper bodies for a more boyish look, and during different periods might focus on the waist, leaving the breasts entirely out of it (But still covered), and sometimes going all the way down to shape the upper hips.
The corset wasn't in style during the entire four hundred years of its popularity. Mary, Queen of Scots, didn't wear it, and the French aristocracy dropped the look during several turbulent periods (Yes, including the revolution).
But it should be noted that while these corsets were uncomfortable, they weren't tightlaced, in other words, they would not deform the shape of the body when the corset wasn't worn.
Then, in the 1840s and 1850s things got nuts. When you think of corseting, or waist training, and you picture the teeny-tiny waist that your doctor warns you about because your intestines are smooshed, you're thinking of mid-Victorian corsets. While corsets had always been tight-ish, during this period things became extreme. How extreme? Try Victorian Dress Reform extreme. During the mid to late Victorian era, from 1850-ish to 1900, tons of women, doctors, public figures and the like came out against tightlacing of the corset. This was actually a revolutionary period that produced bloomers and ladypants and other advances that allowed women freedom for sport and work and etc.
Aside from fetish wear, the fashion of the corset died out in the early 20th century, killed mostly by feminism. It's no accident that once women went to college and fought for the right to vote they started stripping off layers of discomfort as they went.
The trend was carried on by a few celebrities of the day. One, a French dancer named Polaire (1874-1939), also began to wear piercings like nose rings as part of her provocative act. The reason for the nose ring?
"People are becoming barbarians. The dancing of the tango shows it – so do lots of other things in our twentieth century civilization," she said. "I admit it frankly. I am a barbarian. I put a ring in my nose so everyone shall know it."
Following Polaire, Ethel Granger made waves by having the smallest waist ever recorded, at 13 inches, or a couple inches less than my arm measures. And yes, I just looked at my arm and thought about how weird that was. Granger also made a habit of wearing a lot of different piercings, including nostril, septum, cheek and nipple piercings, along with a whole host of ear piercings and stretched earlobes. One early photo of her shows her with two nose rings and a septum tusk, along with her tiny, tiny waist. And she did this during the 1940s and 1950s. According to biographers, Ethel did all this at the behest of her husband, who was into obscure (at that time) fetish items. Whether their relationship is seen as a lifelong domination-submission fetish thing, or a cruel form of modern slavery depends on who's writing the article.
But the fact that her husband was heavily into the (then magazine based) fetish industry shows that these items were already well entrenched in fetish culture in the 1930s when Ethel first began trying them out.
There were short periods, like the 1820s and 1890s, where corset were worn by men to slim the waist. For the most part this was a "lose that gut" type of thing, except for the 1820s, when a wasp waist actually became popular, briefly, for men.
As for the dangers, you can be assured that most doctors do not think that you should tightlace a corset to slim your waist. In extremes, it can deform the lower ribs, cause you to have indigestion, constipation, weird folds in your liver, and shallow breathing that can lead to passing out.
But will it kill you? Most of the women famous for tightlacing, including Ethel Granger, lived to be as old as their period of history might expect. During the Victorian Reform period, many doctors claimed the corset was responsible for diseases ranging from tuberculosis to cancer. Today, many doctors warn of issues like blood clots. In 1903 a woman died when she was impaled by two of the "ribs" of her corset, if that counts.
As for deaths, it's said that waist training too fast can cause shock and death, and that the constipation can also cause death, though I didn't find any concrete examples of either. Most of the old timey deaths seem to be from the passing out, which if you're on the stairs or near water can easily result in untimely death.
But if you really want to, I haven't found any solid evidence that you shouldn't. Just take your time, and stay away from stairs.