14. A Strange Sickness That Mysteriously Appeared, Then Vanished
A new disease is known as the “sweating sickness” suddenly appeared in the late Middle Ages, with the first appearance in England, after which it spread to continental Europe. A mysterious illness, the sweating sickness struck in epidemic waves over a seven-decade period, then vanished just as suddenly as it had emerged. Little is known about the incubation period, but when the symptoms cropped up, they and their consequences were sudden, and usually devastating: death frequently occurred within just a few hours.
Initial symptoms included a sense of dread, followed by shivering, headaches, giddiness, exhaustion, nausea, and severe pains in the neck, back, shoulders, and limbs. Then came the symptom that gave the disease its name: copious sweat. That was often accompanied by abdominal pains and delirium. Severe symptoms typically lasted for 15 to 21 hours, and often culminated in a coma or death. Unusual among illnesses, the sweating sickness disproportionately struck the upper classes. Today, various theories ascribe the mysterious disease to hantavirus, influenza, typhus, or botulism. However, there is no definitive answer yet as to just what the sweating sickness might have been.