Between 1485 and 1551, England was hit by at least five  epidemics of a disease called sweating sickness.

And, sure, lots of illnesses can make you sweat… from food poisoning to the flu. But sweating sickness was much  worse than its name would suggest.

Symptoms like aches, fatigue, and, yes, sweating would get bad quickly, and you could die in just a few hours! Each epidemic of sweating  sickness lasted several months and killed hundreds of people. But after the 1550s, the  disease completely disappeared.

Or did it? Researchers are working with  some pretty spotty recordkeeping. But that hasn’t stopped them f rom trying to figure out exactly what  caused this mysterious, fleeting disease. [INTRO MUSIC] Let’s set the scene a little bit.

The 1485 epidemic struck at the  tail end of the Middle Ages, more than a century after the Black Death killed a third of the entire population of Europe, and a few decades after the Hundred Years’ War, during which time a lot of people  died for entirely different reasons. 1485 was also the year that Henry VII became king and founded the Tudor dynasty. His family plays a minor role in this  story, so we’ll be coming back to them. Meanwhile, the field of medicine  was still pretty medieval.

There were barber-surgeons who could  cut your hair, pull your teeth, or do some bloodletting. And basically anyone could  claim to be a physician, whether they had actually studied  medical history at a University or…just gave out advice based on vibes. By the mid-1500s, Europe was now  solidly in what historians call the Early Modern period.

So, technically not medieval. And Henry VII’s son, Henry  “I want a divorce!” VIII was both head of England and head  of the new Church of England. Henry VIII also established what’s now called the Royal College of Physicians, as well as the Guild of  Barbers and Surgeons of London, to help regulate medical training a little better.

But there was still plenty of  vibes-based medicine happening, and we still didn’t have a good  understanding of microbiology. All this to say, the 15th and 16th centuries  were not the best time to get sick. Honestly, even the original documents from  the time should be taken with a grain of salt.

Even when physicians wrote down their  observations about sweating sickness, the field of medicine was changing around them! And when modern researchers  dig into these sources, it’s important to think about whose  lives and deaths were being recorded, and whose were ignored. The puzzle pieces researchers use to  understand the mystery of sweating sickness come from three main buckets of primary sources.   First, any letters and newspapers  that happen to mention the disease.

Which didn’t just go by “sweating sickness”. This thing went by a bunch of names, including Sudor Anglicus, the English Sweat, or just “the sweat”. Second, a couple of fairly reputable  physicians wrote down eyewitness accounts.

A French physician named Thomas  Forestier lived in England around the first epidemic in 1485 and  published two treatises about the sweat. And there’s a whole book about the 1551 epidemic and the history of sweating sickness by an English physician who  tried on different names throughout his lifetime. We’ll just call him John Caius.

The third bucket of primary sources is  a patchy collection of parish registers. These local church records ramped up  around the time of Henry VIII’s reign, and documented important life  events like marriages and deaths. By stitching these accounts together, researchers think there were five  summers between 1485 and 1551 when sweating sickness spread fast and far enough to be classified as an epidemic in England.

Outbreaks usually peaked in June to August, but one was recorded as early  as April and another lasted as late as December. In 1529, the disease raged across  the entire continent of Europe. But before I tell you about  what happened next, a quick ad.

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You can give it a try for free at  brilliant.org/scishow, the QR code onscreen, or the link in the video description. You’ll also get 20% off an  annual premium subscription. Wherever and whenever “the sweat” popped up, it struck suddenly and intensely.

The symptoms made you miserable, fast: aches and chills, fever,  fatigue, intense stinky sweating, and difficulty breathing… to name a few. And like I mentioned earlier,  death could happen within the day, possibly due to intense  dehydration from all that sweating. It’s a little hard to estimate  how likely you were to die, so there are numbers ranging from 5% to 90% in different modern-day papers.

Although many researchers land  somewhere between 30 and 50%. This variation could be from lots of factors, like the quality of record-keeping, whether people lived in urban city  centers or the rural countryside, or the quality of medical care… …including some physicians who  may have made things worse. We can thank John Caius for his record-keeping, but he and other physicians had some  questionable treatment suggestions.

They wanted to make these  patients sweat out the disease, whether by piling clothes on top of them, or rubbing their skin or giving them warm drinks. Caius also recommended keeping  them awake at all costs, by making them smell vinegar and rosewater, slapping them with rosemary sprigs, or pulling on their ears, nose, or hair. Because that was the state of medicine, it’s no surprise there were all kinds of hot takes about what caused sweating sickness, too.

Some blamed evil air, or the physical  filth inside and outside of homes. Others pointed at religious  causes, like a disaster from God, or being a Lutheran, or being…uh…Catholic. Oh right I forgot to mention  all the religious turmoil that England was swimming in at the time.

Which is only partially the Tudors’ fault. A handful of contemporary  records seemed to say that rich, young men were most likely to get sick, whether or not that was actually true. Again, the record-keepers could have been biased.

But also, when people get  violently sick and die suddenly, survivors might exaggerate  just how bad everything was. In any case, we know that sweating  sickness freaked people out, especially Henry VIII. There are reports of him fleeing London in 1517 and again in 1528 to avoid those two epidemics, even as members of his household got sick.

Including Anne Boleyn and her dad! So that’s at least one thing  Showtime’s series The Tudors managed to get historically accurate. It’s a little hard to tell what  happened to sweating sickness  after 1551.

Diseases come and go throughout history as humans build immunity and microbes mutate. So it could’ve disappeared  as mysteriously as it arose. But we also might be missing records, or this collection of symptoms might’ve been called something  else as time went on.

One paper published in 2018 seems  to have found a bunch of sources throughout the 19th century that  point to cases of sweating sickness from 1483 all the way to 1802. Whether sweating sickness is gone for good, or still around under a different name, scientists love a good mystery. And now that we have the power of microbiology… and much more robust medical knowledge… there’s lots of speculation out there.

Researchers have thrown out a laundry list of bacterial and viral suggestions that cause sweating and those other symptoms, from anthrax to influenza. But the most recent hypothesis  revolves around Hantavirus: a family of viruses named after  the Hantan river in South Korea. The timing of the English outbreaks… for a few months after a wet spring season… sort of resemble epidemics that  were spread by hantavirus vectors… namely, rodents.

And the symptoms mirror the intensity of a disease called Hantavirus pulmonary syndrome. But that being said, it’s still speculation. We can’t just go gravedigging in a parish where people died of sweating sickness.

And not just for ethical reasons. While we can sometimes extract and  amplify really old DNA fragments from human tissue, the RNA that makes up hantavirus genomes isn’t a very stable molecule by comparison. In the super rare occasions that  we have found preserved viral RNA, it’s been on ice in permafrost, not in the fluctuating temperatures  of the English countryside.

And even then, any old RNA data we have isolated has been tricky to verify. One of the most frustrating things  about historical medical mysteries is that we may never know what diseases these now-dead people contracted, because we can’t use our modern tools, and any records we have are always  going to be flawed in some way. But that doesn’t stop scientists and historians from sweating the details and trying to find out. [ OUTRO ]