Sweating Sickness: The Forgotten Epidemic

The Sleeping Beauty, by John Collier

During medieval times, diseases were a constant threat to people’s health, brought about by lack of hygiene and poor understanding of the nature of the illness. The myriad diseases that plagued and perplexed medieval physicians are well understood today, but one that remains a historical and medical mystery is the English sweating sickness.

In the 15th and 16th centuries, a mysterious epidemic swept across Europe. Victims of the disease first came down with fever and cold shivers, along with headache, severe pains in the neck, shoulders, and limbs, and great weakness. The cold stage lasted from half an hour to three hours, after which the hot phase started. This was characterized by profuse sweating and thirst, accompanied by delirium, rapid pulse, palpitation and chest pain. In the final stages, the victim would collapse and fall asleep, never to wake up again. The most terrifying aspect of the sweating sickness was the speed with which it killed. Most victims were dead within 18 hours after the first onset of symptoms. Only those who survived the first 24 hours went on to make a full recovery.

The sweating sickness came in five major outbreaks between 1485 and the last documented outbreak in 1551. A more benign variant of the same disease, known as Picardy Sweat, then broke out in Northern France between 1718 and 1874. During this time, there was nearly two hundred outbreaks of the illness, but the mortality rate was much lower.

The disease struck the first time during the reign of Henry VII, in 1485, right after the Battle of Bosworth. It killed more than ten thousand people within a single month. A less widespread outbreak occurred in 1507, followed by a third and much more severe epidemic later that year which also spread to France. The third outbreak was fatal killing half the population in some areas. The fourth outbreak broke out in London in 1528 and speedily spread over the whole of England. Henry VIII reportedly fled London in order to prevent contracting the disease, and hopped from one residence to another, sleeping in a different bed each night. The disease then appeared in Hamburg as suddenly as it did in London, and spread so rapidly that more than a thousand people died within a few weeks. It swept throughout Europe, reaching Switzerland, Denmark, Sweden, Norway, Lithuania, Poland, and even far east into Russia. The disease made its last appearance in 1551.

A peculiar characteristic of the malady was that it struck especially the wealthy and the upper class. Dukes, bishops, and mayors, all fell victims to it. Monasteries were hit the hardest and fatalities among the clergies were high. The disease even affected the royal household. Anne Boleyn, the wife of King Henry VIII, is said to have contracted and survived the disease. The mysterious death of Arthur Tudor, the eldest son of Henry VII of England, has also been attributed to sweating sickness. The disease’s association with the upper class caused the illness to be nicknamed “Stop Gallant” because it apparently stopped so many young gallants.

Modern scholars suggest that the disease may have been caused by an unknown hantavirus that rodents carry without themselves becoming infected by it. In humans, hantavirus causes fatal pulmonary infection that induces flu-like symptoms such as fever, cough, muscle pain, headache, and lethargy. Mortality rate is as high as 36 percent.

Another suspect is arbovirus, spread by tick and mosquitoes. The sweating sickness seemed to appear after periods of prolonged rainfall and extensive flooding in some areas. Indeed, some contemporary scholars blamed the wet English climate for the disease. If arbovirus is the cause, it could explain why the higher, colder parts of the British Isles—Scotland and Wales—remained unaffected.

Other hypothesis ranged from food-borne botulism, food poisoning caused by a fugus, to anthrax. In the end, it is difficult to say what exactly was the sweating sickness. Like most epidemic, it disappeared as suddenly as it appeared, except for a couple of isolated incidents—one in Tiverton, in 1644, claimed the lives of 443 people. The only disease that bears any resemblance to the sweating sickness is the Picardy Sweat, or “military fever”, that caused numerous outbreaks in Germany, Belgium, Austria, Switzerland and Italy in the 18th and 19th centuries.

Incidence of hantavirus outbreak in modern times is relatively rare. During the Korean War (1950–1953), the Korean hemorrhagic fever that swept among the troops was caused by a hantavirus infection. One in out of every ten that fell ill, died. That was the first time the virus was discovered. Its name comes from Hantan River in South Korea. Since then, there has only been a handful of cases throughout the world.