Philip R. Liebson, MD
Rush University, Chicago, Illinois, United States

Portrait of Henry VIII of England

Portrait of Henry VIII, c. 1537
Hans Holbein the Younger
Oil on canvas
11” × 8”


In the recent semi-fictional work by Hilary Mantel, Wolf Hall, which takes place in the early 16th century, the protagonist Thomas Cromwell, counsel and henchman of Henry VIII, awakens in the morning to find his wife sleeping, but the sheets are damp.1 “She is warm and flushed.” He goes to his law office and returns in the evening to find that torches are burning in his house. His wife is dead. The bedroom is “lively with the scent of the herbs they are burning against contagion.” The following year “the sweat” returns to London and he sends his two daughters out of London. They also eventually succumb to sweating sickness. The king also “tries to outride the plague.” Cardinal Wolsey “seals himself off from the world. Only four servants are allowed to approach him.” It should be noted, although not described in the book, that the cardinal as well as Anne Boleyn were affected by the disorder yet survived. This strange and markedly fatal malady recurred periodically in the late 15th and 16th centuries, primarily in England, and disappeared completely late in the century. It is impossible to determine the cause, but many have speculated about its origins.

The outbreaks of sweating sickness

The years from 1485 to 1603 were the age of the Tudors, perhaps a golden age in England. It was the time of Henry VIII and Elizabeth I; of Sir Thomas More, lawyer and Lord Chancellor; of the birth of Anglicanism, the development of Parliament, the defeat of the Spanish Armada, and the age of Shakespeare; of Edmund Spenser and Christopher Marlowe.

In 1525 the population of England was a little over two million, well below the four million before the Black Death epidemic of 1348.2 England was to reach a population of four million around 1600, but the bubonic plaque was a frequent visitor and produced another major epidemic in 1665. Rapid death from infectious disease was common—besides plague there were cholera, dysentery, and smallpox. With the rising population in the 15th century came vagrancy, poverty, and urban squalor. Most of the plagues of that time primarily affected the poor rather than the well-to-do, who could afford to flee to the countryside or wherever the disease had not yet appeared.

The year 1485 saw the beginning of the reign of Henry VII. His arrival in London in late August was followed immediately by the onset of the mysterious plague that caused numerous deaths and became known as sweating sickness.3 Although similar to the Black Death, in that mortality was high and rapid, it was not associated with buboes but with the notable great sweats that gave the malady its name. The cause at the time was attributed by some to the usual suspects: the sins of the people, the configuration of the stars and planets, mysterious vapors, magic spells, and the French. Others considered much more prosaic causes such as the filth and sewage all pervasive in London at the time.

At the end of the War of the Roses in England, French mercenaries were recruited by the Duke of Richmond, the future Henry VII, to fight the current king, Richard III. It was therefore thought that these French freebooters who accompanied the duke to England at the Battle of Bosworth in August 1485 were responsible for introducing the disease into England.3 There was no evidence, however, that the malady was found in France at the time, and in fact, the sickness in its recurrences was mostly confined to England. It was also postulated that the disease could have developed among the armies during their encampment in a marshy area at Litchfield. Here again, one must conclude that a new disease developed unless the army, previously unexposed to microbes in that environment, developed an unusual form of a previously mild disease that was endemic there.

An interesting observation at the time of the first outbreak was that sweating sickness, unlike other plagues, was more common in the rich than in the poor, undermining the theory that filth and sewage were partially responsible. Lice and ticks, however, were also close neighbors of the wealthy at the time, so arthropod-borne infection was a strong possibility.

After the initial epidemic in 1485, four further epidemics occurred in England in 1506, 1517, 1528, 1529 (recounted in Wolf Hall), and 1551. The only time the epidemic reached France was in 1517 in Calais—interestingly, Calais was part of England at the time. The epidemic of 1528-1529 did occur in continental Europe, but not France. In August 1529 a German ship arrived at Hamburg from another German port with twelve of the German crew dead, followed by a lethal epidemic in Hamburg, as well as Bremen, Lubeck, and Copenhagen. It is possible that this was independent of the English outbreak and may have been initiated in the endemic Scandinavian ports.9

In this era, it was unusual for such a lethal epidemic not to have spread more widely beyond one country, despite the separation of the British Isles from the continent. It is also odd that a disease that recurred periodically should disappear so suddenly. It is possible, however, that the disease became less lethal with increasing immunity in the population and became subclinical or with fewer symptoms to differentiate it from other less lethal diseases. Syphilis and measles are other examples of contagious diseases that initially had high mortality but became less lethal with time.

In 1528, the year of the most virulent appearance of the sweating sickness, Henry VIII was maneuvering with the help of Thomas Cromwell to rid himself of Catherine of Aragon and marry Anne Boleyn. In June of that year, Anne came down with the sweat and Henry wrote to her: “I have to grieve . . . to hear of my mistress’ sickness, whose health I desire as my own, and would willingly bear the half of yours to cure you.”3, 10* His primary physician was away, so he sent her his second-best physician. A recent reviewer of the history of the disease wondered about the king’s love when he offered to share but “half of her illness” and would send only his second-best physician to care for her. This at a time when Henry was travelling throughout England to avoid the sweat. As the French ambassador wrote about Henry who was visiting a household where one of the ladies of the chamber developed the sweat: “The King, in great haste, dislodged and went 12 miles hence.”3, 11

In a second letter to Anne, Henry observed that several others in addition to the lady of the chamber fell ill, but all recovered, and that, in general, few women had this disease, and few of them succumbed to it. This was contrary to the French ambassador’s comment on the great mortality in Canterbury, where he recorded eighteen deaths from the disease in a four-hour period in the household of the Archbishop of Canterbury while he was staying there.3, 12

The panic that the disease provoked was reflected in the king’s flight. In 1551, the Venetian ambassador claimed that London had a general evacuation with shops closed and all business suspended.6 Unlike bubonic plague, which generally struck in a limited number of places and primarily involved the poor, the sweating sickness spread widely, and neither social status nor place of residence appeared to offer protection. The last apparent epidemic occurred in 1551, with extension of the disease along established trade routes.


Portrait of Sir Thomas More and Bishop Fisher

Sir Thomas More and Bishop Fisher, 17th century

Contemporary accounts of sweating sickness

The 1485 epidemic was described and analyzed by a contemporary physician, Thomas Forrestier, in several treatises in English and Latin—the latter for the edification of his fellow physicians, who were apparently more versed in Latin than English. The Latin account was entitled Tractatus Contra Pestilentia Thenasomonem et Dissenterium. His description in English translation could be favorably compared with the poetry of that time:4,

The exterior is calm in this fever, the interior excited . . .
The heat in the pestilent fever many times does not appear excessive to the doctor
Nor the heat of the sweat particularly high . . . .
But it is on account of the ill-natured, fetid, corrupt, putrid,
And loathsome vapors close to the region of the heart and lungs
Whereby the panting of the breath magnified and increases
And restricts itself

He distinguished the disorder from plague and other diseases at the time, designating the date of appearance of the disease specifically as September 19, 1485. He described his experience of several days later

We saw two prestys standing together and speaking together, and saw
Both of them dye soddenly. Also in die proxima we se the wyf of a taylour
and soddenly dyed. Another yonge man walking by the street fell down
soddenly. Also another gentylman ryding out of the cyte dyed. Also
many others the which were to rehearse we have known that have dyed soddenly6

A description in 1569 after a later epidemic, by Richard Grafton, described it as:

A newe kind of sickness… through the whole region, which was so sore,
so peynfull and sharp, that the like was never harde of to any mannes
remembrance before that time.7, 8

In an era of religious discontent, the divines were tempted to see the outbreaks in moral terms. Sweating sickness was equated with the death of Edward VI and Mary I's withdrawal of the Anglican Bible and religious service as the plagues of the time. In 1551 the royal government ordered the bishops to propagate the theory that God had sent the epidemic to punish those who rebelled against His will.

The Italian Polydore Vergil, a frequent visitor to England, commented on the disease in Anglicae Historiae, published in 1546, several years before the fifth and final epidemic.3,14 His description of the signs, in addition to continual sweating—which he mentioned was foul smelling—included fever, headache, abdominal pain, and several relapses. This is interesting since many lethal diseases, including plague and smallpox, produced immunity once the victims had recovered. The remedy offered by physicians at the time included bed rest under a light covering for 24 hours with warm fluids. After 24 hours, if the patient was not dead, the treatment was considered effective.

Another treatment advised by Sir Thomas More when his daughter Margaret contracted the disease was a clyster, or enema. She recovered but whether it was due to Sir Thomas’s prolonged prayer for guidance at the chapel or from fluids absorbed from the enema resolving her dehydrated state is a matter for debate.3

Aside from the references to letters, chronicles and other contemporary literary documents to provide information about the sweating sickness, the primary contemporary source of clinical information about sweating sickness is A Boke or Counseill Against the Disease Commonly Called the SWEATE, published by John Caius in 1552, the year after the last epidemic. He was a physician who had studied under the anatomist Vesalius in Padua and practiced and taught medicine. Caius’ description follows:

This disease is not a Sweat onely (as it is thought and called), but a feuer, as I saied, in the spirites by putrefaction venomous . . . . First by the peine in the backe or shoulder, peine in the extreme partes, as arme, or legge, with a flusshing, or wind, as it semeth to certeine of the pacientes, flieng in the same . . . . Secondly by the grief in the liuer and the nigh stomacke. Thirdely, by the peine in the head, & madness of the same . . . . Fourthly by the passion of the hart . . . . Whereupon also followeth a maruelous heauiness, (the fifth token of this disease), and a desire to sleape, neuer contented, the senses in al partes beynge as they were bounde or closed vp, the partes therefore leaft heuy, vnliushe, and dulle . . . . Laste foloweth the shorte abidinge, a certaine Token of the disease.3, 15

In medical parlance, this description suggests myalgia, headache, delirium, cardiac palpitation, tachycardia, tachypnea, chest pain, agonal breathlessness, and death.4

Parish records are another resource useful for documenting the spread of the disease. Although these are uneven, they recorded burials from the autumn of 1538, thus providing some information about the last epidemic in 1551. In 1997, Alan Dyer analyzed the records from 1551 in the 680 parish records available and evaluated registers from a substantial area of the country.16 Although the analysis of these documents is somewhat problematic, given the small size of parishes, these records depict a concentration of burials over a very short period of time, usually a week or two. The records also provide information such as “dyed of ye sweating sickness as yt semeth” of 13 deaths, 9 of whom were buried over 3 days, and “nine persons were buried . . . of ye sweatings sickenes.” Other descriptions for the sweat deaths included “ex sudore,” “in tempore plage sudoris,” and “the hote sicknes called Stupgallant.” Another popular name for the disease was “stoupe knave and know thy master.” The last two refer to “the self-confidence of youth and good social position being deservedly humbled.” In these cases, deaths occurred during the summer months over a short period of a week or less. In London’s twenty-eight parishes, 90% were concentrated in the ten days between July 10 and 20.

Although burials attributable to the disease typically occurred over a short period, in some cases there was a gap of a week or two between two streams of disease-related burials. These incidents were commoner in southern England and may have been due to reinfection of a parish from a neighboring one. The records show that although September was the end of the primary epidemic, there were minor episodes in late October in both the north and south.

The records allowed analysis by sex and age, but not necessarily by social position. Accounts from London in 1551 reflect the general contemporary impression that males were predominantly involved. Not one parish had a majority of women buried from the disease, and in two sample records more than 80 percent of burials were of males. Over the rest of the year, when the sweat was not responsible, the burials were equally matched by sex. The age distribution was more difficult to evaluate because of a lack of details beyond the name of the victim. The provincial records seem to indicate that the elderly were generally spared and that most victims were young or middle-aged adults. The records also indicate that characteristic records of the sweat did occur intermittently, such as in 1545 and 1552. The mortality rates at the time were reported at second-hand, with significant exaggeration of the number of deaths. For example, at the height of the epidemic of 1528, the mortality reports do not indicate hundreds of thousands of excess deaths in London. A study of records and wills in 1551 during the epidemic in Chester showed no marked changes in mortality. Thus, the records from that year indicate that the sweating sickness did not contribute to the excesses of mortality that would be seen with the recurrences of plague.

Although the virulent sweating sickness never appeared in France during the English epidemics through 1551, there was a condition called the Picardy sweat that had been endemic in that province of northeastern France since 1578.17 Occurring frequently between 1718 and 1874 (200 epidemics during that period), it was much milder than the English sweating sickness and presented with a rash. Up to 30 percent of the population of the area were affected. A similar illness, trench fever, developed among Allied troops in that area during World War I and was possibly caused by a rickettsia.


Portrait of John Caius

Portrait of John Caius, early 19th century

Retrospective analyses of sweating sickness

After the periodic epidemics subsided in the middle of the 16th century, nothing more was heard of them until the mid-19th century, when a German physician and medical writer, Justus Hecker, wrote a treatise, The Epidemics of the Middle Ages, which described about plague, smallpox, the dancing mania, and sweating sickness. Relying on primary sources, Hecker subscribed to the belief of some contemporaries of the Tudor period that the army of the Duke of Richmond incubated many diseases, of which sweating sickness was but one manifestation.3, 18

The next commentary about sweating sickness was written by Charles Creighton, a London pathologist who wrote A History of Epidemics in Britain in 1894. He also summarized primary sources of the sweating sickness epidemics and commentaries from the earlier period referring to the disease.3, 19 Creighton designated September 27th as the beginning of the first epidemic, a week later than Thomas Forrestier’s date. It is difficult to reconcile the beginning of the epidemic at that precise period in September when it was already raging in August, according to contemporary observers. However, his investigation did uncover that the Mayor of London, his successor, and several City Council members died of the illness within a week of that date. In regard to the possibility that the French insurgents with the Duke of Richmond brought the sickness to England in 1485, there is evidence that the disease may have been raging as early as June in York, well north of Bosworth and London. Creighton was skeptical about the heavy mortality from the disease itself. He reflected the previous theory that some agent, possibly a virus, had been imported from Picardy with the mercenary army in 1485; he further noted that the five epidemics in England had followed particularly rainy seasons.

In the 20th century authors have attributed sweating sickness (in chronological order) to relapsing fever, influenza (during the 1918 flu pandemic), food poisoning or wheat fungus, an enterovirus or arbovirus, and even to anthrax. These explanations are, in many ways, imperfect. Relapsing fever has a short incubation period, and its onset is sudden and severe. But sweating is not a feature, and the jaundice associated with this spirochetal etiology is not a feature of the sweat. In addition, influenza presents with respiratory signs uncommon in sweating sickness.

The possible viral etiology was proposed in a paper published in 1981 by AH Wylie, a theologian from the University of Exeter, and Leslie H Collier, a London physician.6 Like previous writers, they attributed the epidemic to the French army, but further argued that the disease was introduced to the north of England from Scandinavia and Russia. Wylie contributed ecclesiastical records from that period indicating that Lord Stanley, a compatriot of Richard III, excused himself and his army from joining the Battle of Bosworth because Stanley’s army in the north of England had sweating sickness. An account in the York Civic Records in June 1485, three months before the Battle of Bosworth, also mentioned a pestilence in the area. As it was too early in the season for the Black Death; this pestilence was conceivably sweating sickness.

Wylie and Collier provided considerable detail from primary sources about the 1551 outbreak. They corroborated previous observations: sweating sickness began abruptly in early summer and ended in September; it spread widely throughout England; it was more common in men than in women and rare in young children; it particularly affected the wealthy, possibly because they were spared infection from other major plagues; and it did not appear to be associated with overcrowding, as the disease was usually more prevalent in the open countryside. The abrupt end of the outbreak by the end of September suggested an unidentified rodent reservoir of the virus. They concluded that an arbovirus was the most likely cause, citing the abundance of heavily-wooded areas of England capable of sheltering infected mammals.

In an article in the Journal of Medical Biography in 1998, Frederick Holmes suggested hantavirus as a cause of sweating sickness.3 Hantavirus is similar to sweating sickness, in that there is a relatively rapid onset, early high mortality (51 percent), and often respiratory failure. It is also is preceded by increases in small rodent populations due to wet weather, which is also a characteristic of the years just before sweating sickness epidemics. Holmes concluded that rodents spread hantavirus from Siberia and Russia through Scandinavia in the 15th century, infected England before 1485 through the northern ports, became endemic in northern England, and became epidemic in 1485. This theory, however, is problematic. As Holmes himself noted about a 1993 outbreak of the hantavirus in the southwestern US among young Native Americans, there were few symptoms or signs suggestive of sweating sickness.

The possibility of a hantavirus causing sweating sickness was also examined in a paper by Eric Bridson in the British Journal of Biomedical Science in 2001.7 Arboviruses are associated with cutaneous hemorrhagic signs, unlike the sweating sickness. Hantavirus causes a hemorrhagic disease with renal failure common and a 10 percent mortality rate. It was first encountered in Western medicine during the Korean War when 3,000 US troops were infected. Similar to the 1993 Native American epidemic in the Southwestern US, the virus appeared rodent-borne. At present, hantavirus-infected rats have been found in major cities in the US. Unfortunately, there is no evidence for how sweating sickness was transmitted in the 16th century, and the lack of hemorrhagic signs or respiratory symptoms would tend to negate the possibility of a hantaviral cause.

Interestingly, a more recent paper in 2004 referred to the five deaths in the United States in 2001 when spores of Bacillus anthracis were deliberately sent through the mail.20 Among the 13 persons who became ill, a prominent symptom was profuse sweating.

In summary, sweating sickness was a strange new disease confined primarily to England, with several epidemics from the late 15th century to the early 16th century. Although its mortality rate was high, there was no significant effect on the size of the general population. Several authors have speculated its cause, but there is yet no consensus. The mystery might finally be solved by exhuming victims to look for evidence of spores or RNA. Indeed, Henry Brandon, Duke of Suffolk died during the epidemic of 1551 and was buried in a cemetery that still exists. Although the search for hantavirus RNA is feasible, this genetic material is unstable and the odds of its survival are low, so the duke’s grave will not likely be disturbed. Thus, the cause of sweating sickness remains a medical mystery, still waiting to be unlocked.


*When two reference numbers are used together, the first is the source the author used and the second is the original source.

  1. Mantel H. Wolf Hall. New York: Picador 2010.
  2. Morgan KO. The Oxford history of Britain. New York: Oxford University Press; 1984. Chapter 5, The Tudor Age (1485-1603) pp 257-326.
  3. Holmes FF. Anne Boleyn, the sweating sickness, and the hantavirus: a review of an old disease with a modern interpretation. J Med Biography. 1998;6:43-484
  4. Thwaites G, Taviner M, Gant V. The English sweating sickness. N Engl J Med 1997;336:580-582
  5. Forrestier T. Tractatus Contra Pestilentia Thenasomonen et Dissenterium, Rouen, 1490.
  6. Wylie JAH, Collier LH. The English sweating sickness (Sudor Anglicus): A reappraisal. J Hist Med. 1981;36:425-435.
  7. Bridson E. The English ‘sweate’ (Sudor Anglicus) and hantavirus pulmonary syndrome. Br J Biomed Sci. 2001;58:1-6.
  8. Grafton R. A chronicle at large and mere history of the affayres of England. London: H. Denham; 1569.
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  10. Public Record Office. Henry VIII to Anne Boleyn, 16 June 1528. Calendar of State papers, Foreign and Domestic, of the Reign of Henry VIII. London: HMSO; 1876: no. 4383
  11. Public Record Office. Du Bellay to Montmorency, 18 June 1528. Calendar of State papers, Foreign and Domestic, of the Reign of Henry VIII. London: HMSO; 1876: no. 4391
  12. Public Record Office. Du Bellay to Montmorency, 21 July 1528. Calendar of State papers, Foreign and Domestic, of the Reign of Henry VIII. London: HMSO; 1876: no. 4542.
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  14. Vergil P. Urbinatus Anglicae Historiae Libri Vigintiflex. Basilae: Apudimich Isingrinum; 1546.
  15. Caius J. A Boke or Counsell against the Disease called the SWEATE; 1552.
  16. Dyer A. The English sweating sickness of 1551: An epidemic anatomized. Med Hist. 1997;41:362-384.
  17. Roberts L. Sweating sickness and the Picardy sweat. B Med J. 1945; Aug 11 196.
  18. Hecker JFC. The epidemics of the Middle Ages [Babington BG, trans]. London: George Woodfall and Son, 1848:331-338.
  19. Creighton C. A history of epidemics in Britain, vol. 1 (2nd Ed) 1894. See London: Frank Cass, 1965:237-281.
  20. McSweegan E. Anthrax and the etiology of the English sweating sickness. Medical Hypotheses 2004;62:155-157.

PHILIP R. LIEBSON, MD, graduated from Columbia University and the State University of New York Downstate Medical Center. He received his cardiology training at Bellevue Hospital, New York and the New York Hospital Cornell Medical Center, where he also served as faculty for several years. A professor of medicine and preventive medicine, he has been on the faculty of Rush Medical College and Rush University Medical Center since 1972 and holds the McMullan-Eybel Chair of Excellence in Clinical Cardiology.