The text below describes a disease that was particularly common in England during the 15th and 16th centuries; also known as the Sudor Anglicus, or English sweating sickness it is now suggested that it could have been a form of hantavirus. Extracted corrected and formated from the entry for Sweating-Sickness in the 1911 Encyclopedia Britannica, the text of which lies within the public domain.

A remarkable form of disease not known in England before, attracted attention at the very beginning of the reign of Henry VII. It was known indeed a few days after the landing of Henry at Milford Haven on the 7th of August 1485, as there is clear evidence of its being spoken of before the battle of Bosworth on the 22nd of August. Soon after the arrival of Henry in London on the 28th of August it broke out in the capital, and caused great mortality. This alarming malady soon became known as the sweating-sickness. It was regarded as being quite distinct from the plague, the pestilential fever or other epidemics previously known, not only by the special symptom which gave it its name, but also by its extremely rapid and fatal course.

From 1485 nothing more was heard of it till 1507, when the second outbreak occurred, which was much less fatal than the first. In 1517 was a third and much more severe epidemic. In Oxford and Cambridge it was very fatal, as well as in other towns, where in some cases half the population are said to have perished. There is evidence of the disease having spread to Calais and Antwerp, but with these exceptions it was confined to England.

In 1528 the disease recurred for the fourth time, and with great severity. It first showed itself in London at the end of May, and speedily spread over the whole of England, though not into Scotland or Ireland. In London the mortality was very great; the court was broken up, and Henry VIII left London, frequently changing his residence. The most remarkable fact about this epidemic is that it spread over the Continent, suddenly appearing at Hamburg, and spreading so rapidly that in a few weeks more than a thousand persons died. Thus was the terrible sweating-sickness started on a destructive course, during which it caused fearful mortality throughout eastern Europe. France, Italy and the southern countries were spared. It spread much in the same way as cholera, passing, in one direction, from north to south, arriving at Switzerland in December, in another northwards to Denmark, Sweden and Norway, also eastwards to Lithuania, Poland and Russia, and westwards to Flanders and Holland, unless indeed the epidemic, which declared itself simultaneously at Antwerp and Amsterdam on the morning of the 27th of September, came from England direct. In each place which it affected it prevailed for a short time only generally not more than a fortnight. By the end of the year it had entirely disappeared, except in eastern Switzerland, where it lingered into the next year; and the terrible English sweat has never appeared again, at least in the same form, on the Continent.

England was, however, destined to suffer from one more outbreak of the disease, which occurred in 1551, and with regard to this we have the great advantage of an account by an eyewitness, John Kaye or Caius, the eminent physician.


The symptoms as described by Caius and others were as follows.

The disease began very suddenly with a sense of apprehension, followed by cold shivers (sometimes very violent), giddiness, headache and severe pains in the neck, shoulders and limbs, with great prostration. After the cold stage, which might last from half-an-hour to three hours, followed the stage of heat and sweating. The characteristic sweat broke out suddenly, and, as it seemed to those accustomed to the disease, without any obvious cause. With the sweat, or after that was poured out, came a sense of heat, and with this headache and delirium, rapid pulse and intense thirst. Palpitation and pain in the heart were frequent symptoms. No eruption of any kind on the skin was generally observed; Caius makes no allusion to such a symptom. In the later stages there was either general prostration and collapse, or an irresistible tendency to sleep, which was thought to be fatal if the patient were permitted to give way to it. The malady was remarkably rapid in its course, being sometimes fatal even in two or three hours, and some patients died in less than that time. More commonly it was protracted to a period of twelve to twenty-four hours, beyond which it rarely lasted. Those who survived for twenty-four hours were considered safe.

The disease, unlike the plague, was not especially fatal to the poor, but rather, as Caius affirms, attacked the richer sort and those who were free livers according to the custom of England in those days. "They which had this sweat sore with peril of death were either men of wealth, ease or welfare, or of the poorer sort, such as were idle persons, good ale drinkers and taverne haunters."


Some attributed the disease to the English climate, its moisture and its fogs, or to the intemperate habits of the English people, and to the frightful want of cleanliness in their houses and surroundings which is noticed by Erasmus in a well-known passage, and about which Caius is equally explicit. But we must conclude that climate, season, and manner of life were not adequate, either separately or collectively, to produce the disease, though each may have acted sometimes as a predisposing cause. The sweating-sickness was in fact, to use modern language, a specific infective disease, in the same sense as plague, typhus, scarlatina or malaria.

The only disease of modern times which bears any resemblance to the sweating-sickness is that known as military fever ("Schweiss-friesel," "suette miliaire" or the "Picardy sweat"), a malady which has been repeatedly observed in France, Italy and southern Germany, but not in the United Kingdom. It is characterized by intense sweating, and occurs in limited epidemics, not lasting in each place more than a week or two (at least in an intense form). On the other hand, the attack lasts longer than the sweating-sickness did, is always accompanied by eruption of vesicles, and is not usually fatal. The first clearly described epidemic was in 1718 (though probably it existed before), and the last in 1861. Between these dates some one hundred and seventy-five epidemics have been counted in France alone.


For history see Bacon's Life of Henry VII, and the chronicles of Grafton, Holinshed, Baker, Fabyan, etc. The only English medical account is that of John Caius, who wrote in English A Boke or Counseill Against the Disease commonly called the Siveate, or Sweating Sicknesse (London, 1552); and in Latin De ephemera (Louvain, 1556; reprinted London, 1721). The English tract is reprinted in Babington's translation of Hecker's Epidemics of the Middle Ages (Syd. Soc., 1844). This also contains Hecker's valuable treatise on the English sweat, published in German (1834), and also printed in his Volkskrankheiten des Mittel-alters, edited by Hirsch (Berlin, 1865). Griiner's Scriptores de sudore anglico (Jena, 1847), contains nearly all the original documents, including the two treatises of Caius. See also Hirsch, Handbook of Geographical and Historical Pathology, trans. by Creighton (New Syd. Soc., 1885).

See also: The sweating sickness returns - Sudor Anglicus, English sweating sickness of the 16th century, may have been a hantavirus disease - Brief Article mi_m1511/is_n6_v18/ai_19447779