HUMANITIES | MEDICINE AND SOCIETY
Sweating blood: history and review
n Cite as: CMAJ 2017 October 23;189:E1315-7. doi: 10.1503/cmaj.170756
See related article at www.cmaj.ca/lookup/doi/10.1503/cmaj.161298
T
https://commons.wikimedia.org/wiki/File%3ATaisten-Tabernakelbildstock_04.jpg
credible, though scant, obserhe case report in
vations of sweating blood
this issue of CMAJ 1
persist — as clinical phenomraises two intriguing
ena of unspecified cause, if
questions. First, do humans
not as disease.
really sweat blood? Second,
Regarding the second
what is the medical history
question about the clinical
of this phenomenon?
history of bloody sweat,
Hematohidrosis has made
medical writers often trace it
brief but increasingly fewer
to the story of Christ’s sufferappearances in dermatology
ing as told in the Bible by the
texts. In 1895, Moritz Kaposi
physician evangelist (Luke
defined it as “the occasional
22:44). But hematohidrosis
spontaneous oozing of arteappeared in the scientific litrial blood from the sweat
erature long before.4 As early
glands,” and he cited observations by distinguished predeas the third century B.C., two
cessors, including Ferdinand
treatises by Aristotle conRitter von Hebra.2 Referring to
tained passages about sweat
that either looked like, or
a 1930 article, two editions of
really was, blood.
Rook’s Textbook of Dermatology (1968 and 1992) stated
Instances, indeed, are not
that it was “rare”; however, by
unknown of persons who in con2007, the statement had vansequence of a cachectic state
ished. In 2012 and earlier,
have secreted sweat that resemBolognia and colleagues, in
bled blood (Parts of Animals
[3.5:668]).
their Textbook of Dermatology, declared that “hematidrosis,” as a disorder of sweat
If the blood get exceedingly liquid, animals fall sick; for the
glands, “has not been conblood then turns into something
firmed scientifically,” allike ichor, or a liquid so thin that
though they did not deny its Tabernakelbildstock in Taisten. Christus am Ölberg [Wayside Shrine at Taisten, Italy: at times has been known to
existence. On the other hand, Christ on the Mount of Olives].
exude through the pores like
standard hematology textsweat (History of Animals [3:19]).
based on their careful review of 76 selected
books have long ignored hematohidrosis.
cases published from the 17th century to
When I asked some of my senior hematology
The opinion may have derived from the
1980.3 Historians quake at the irresistible
colleagues at University of Toronto, Toronto,
wisdom that some animals known to the
and Queen’s University, Kingston, Ontario, if
ancients, such as the hippopotamus and
practice of retrospective diagnosis, often
they had seen a case, none had, although
certain horses, secrete red sweat long concalling it futile or condescending, because
two had witnessed bloody tears.
strued as blood. The physiologic possibility
epistemic and social conditions change,
In answer to the first question, then,
of bloody sweat also appeared in the work
diseases mutate and older descriptions
ambivalence is evident. Nevertheless, a
of Aristotle’s successor, Theophrastus (On
lack parameters that are fundamental now:
steady stream of reports prompted the
Sweat, 11–12).5
we must treat the experience of predecesphysician couple Joe E. Holoubek and Alice
sors with respect and use our own views
Many medical writers insist that the
B. Holoubek, both devout Catholics, now
with humility. The Holoubeks navigated
second-century Greek physician, Galen,
deceased, to publish a 1996 classification
these challenges well, reminding us that
described bloody sweat. But this assertion
© 2017 Joule Inc. or its licensors
CMAJ | OCTOBER 23, 2017 | VOLUME 189 | ISSUE 42
E1315
HUMANITIES
stems from the oft-repeated reference to
the pseudo-Galenic Latin text, De utilitate
respirationi. This treatise, which bears the
same name as an authentic but different
text, was paraphrased and popularized by
the physician Richard Mead in his 1749
medical disquisition on the bloody sweat of
Christ: “Contingere interdum, poros ex multo
aut fervido spiritu adeo dilatari, ut etiam
exeat sanguis per eos, fiatque sudor sanguineus. [It sometimes happens that the pores
are so vastly dilated by a copious and fervid
spirit, that even blood issues thro’ them,
and constitutes a bloody sweat].”
The passage does not describe a case;
rather, it repeats Aristotle’s view, emphasizing the etiological role of a “fervid spirit.” It
appears that the authentic Galen did not
witness such a case, although his voluminous opus contains a great deal about
blood and perspiration in relation to respiration. But blood as a humour, and sweat as
its derivative, were of considerable importance in religion and literature throughout
the middle ages.6 Chaucer described a
horse ridden so hard that it “did sweat till
men his coat might wring/His two flanks
were all blood” (“Tale of Sir Thopas”). Skeptics of equine hematohidrosis might wonder about the role of abrasions.
In the late medieval and early modern
periods, several physician authors referred
to bloody sweat, but few presented original cases. Most described its possibility
and plausibility, appealing to the physiologic authority of Aristotle and (pseudo-)
Galen and referring to the passion of
Christ. They include the 12-century Benedictine, William of Saint-Thierry, and the
authors of several medical dissertations in
Latin concerning “sudor cruentus” (bleeding sweat) and “sudor sanguineus” (bloody
sweat). In most of these works, the purpose was to apply scientific knowledge to
assess the plausibility and the naturalness
of the story of the passion (Appendix 1,
available at www.cmaj.ca/lookup/suppl/
doi:10.1503/cmaj.170756/-/DC1).
The scientific preoccupation with
bloody sweat in this period might be
related to a heated controversy surrounding one of the sacred relics of the church.
Since the Middle Ages, the Veil of Veronica
or Sudarium was reputed to be the cloth
used to wipe Christ’s face on his way to crucifixion; it retained an imprint of his fea-
E1316
tures, possibly from sweat, or blood, or
both. Notwithstanding its dubious origins,
the veil was said to have hung in the old St.
Peter’s Basilica and been used in religious
processions from at least the 13th century.
After the 1527 sack of Rome, according to
the scholars I. Wilson and E. Kuryluk, some
thought it had been destroyed; others
claimed it was taken elsewhere or lost,
while yet others maintain it is still in St.
Peter’s. A brisk industry of making and selling copies arose, but by 1617 Pope Paul V
had restricted their manufacture to designated authorities. In 1629, Pope Urban VIII
ordered the destruction of all copies and
excommunication for anyone daring to
own one. The strict regulations surely
enhanced the cachet of these objects. The
parallel outpouring of medical and scientific interest in bloody sweat may have
been stimulated by attempts to verify the
claims of authenticity. It resembles the
recent forensic investigations applied to
the Shroud of Turin and various contenders
for cloths that had once wrapped the same
body, such as the Sudarium of Orviedo.
Notwithstanding their religious overtones, scattered throughout these early
modern medical works appear the first
eyewitness accounts of hematohidrosis, in
what we would recognize as “case
reports.” For example, in 1627, Georg Spörlin, a physician from Basel, reported on a
12-year-old boy with a high fever who
sweated blood through his shirt.7 In 1628,
the papal physician, Paolo Zacchia,
described a young Belgian condemned to
death who, in his anguish, sweated blood
(Quaestiones medico-legales [Lib III, Tit II, Q
II]). Several other writers observed the
same phenomenon in prisoners facing execution. Samuel Ledelius described a case
associated with scurvy.8
“Sudor cruentus” and “sudor sanguineus” appear in 18th- and 19th-century
medical dictionaries. According to the
Oxford English Dictionary, the various
Greek-derived spellings of h[a]emat[oh]
idrosis appeared more recently, in 1854.
Another lesser-used term, “ephidrosis cruenta,” also emerged in the mid-19th century. Because most observations had been
made in women, some 19th-century
authors, citing Gerard van Swieten and
Philippe Pinel, favoured vicarious or suppressed menstruation as the cause; others,
however, including George Gilles de la
Tourette, invoked psychogenic factors and
insisted that hematohidrosis was a product of hysteria.9 Later, doubt about that
disease category itself probably led some
to assume it was factitious.
Religious writers eventually cited the
medical authors, as science lent credibility
to gospel. For example, two theologians
cited Richard Mead: Adam Clarke in his 1831
edition and commentary of the New Testament, and C. George Griffin’s 1846 commentary on the Sufferings of Christ. The accumulation of religious and medical texts all
citing each other influenced an erudite surgeon, J.H. Pooley of Toledo, Ohio, to compose an essay on bloody sweat for Popular
Science magazine in January 1885.10 Drawing upon physician Mead, theologian Clarke
and a number of other unreferenced
sources, Pooley claimed that it had been
described by Aristotle, Theophrastus and
Galen, whom he piously cited in Latin. Then
he briefly summarized more than 40 modern cases. Because this article is readily
available online, pseudo-Galen, masquerading as Galen, is enjoying a renaissance in
recent examinations of the subject.
A century later, the Holoubeks selected
many of Pooley’s cases for their extensive
review. They identified several categories
of conditions associated with hematohidrosis: systemic disease (e.g., scurvy and
lupus), vicarious menstruation, physical
exertion, psychological stress (repeated or
unique), religious stigmatics and idiopathy. With the scant, second-hand descriptions, suspicion of underlying bleeding disorders or malingering remained. Only a
handful of the Holoubeks’ cases came
from the 20th century. Consequently, few
had been investigated to rule out coagulopathy or skin pathology.
A recent review
To assess the frequency of case reporting of
the condition in modern times, a keyword
search on “h[a]ematohidrosis” (also “hematidrosis” or “hemathidrosis”) resulted in a
list of 42 articles: 10 from the Index Catalogue of the Library of the Surgeon General,
published from 1880 to 1935; and 32 from
MEDLINE, published from 1952 to 2016, in
reputable journals (mostly dermatological),
including the International Journal of Dermatology and Blood. Until now, none have
CMAJ | OCTOBER 23, 2017 | VOLUME 189 | ISSUE 42
bloody sweat from normal-appearing skin
on multiple occasions through time, ranging from one month to four years. The most
common sites were forehead, scalp, face,
eyes and ears, but bloody sweat could also
appear on the trunk and limbs, sometimes
heralded by pain or tingling. Several had
associated hypertension or headache. All
were tested to confirm the presence of
blood (as opposed to chemical discoloration) and to rule out bleeding disorders;
only two displayed a coagulopathy (platelet
factor 3 disorder in one patient and vitamin
deficiency in another). Thirteen underwent
skin biopsy, which was normal or showed
nonspecific changes with blood cells in
sweat ducts. At least 15 (54%) had suffered
severe psychological stress, either with
mental illness, such as depression or anxiety, or in the posttraumatic setting, having
witnessed violence at home, school or
beyond (the abduction of a sibling; the
beheading of a neighbour). Most patients
were observed in one or more episodes by
multiple medical observers whose suspicions that the symptom might be factitious
were allayed. Vasculitis was hypothesized
as an underlying cause in two cases, but
never proven by biopsy. More often, the
examples pointed to psychosomatic origins
in mental anguish, the “fervid spirit” of
pseudo-Galen via Mead. Some authors
hypothesized varying sympathetic activity
on microvasculature.
As for treatment, β-blockers were
effective in six patients. Anxiolytics and
antidepressants were also used in some,
with variable results. An atropine skinwipe produced symptomatic relief for
another; one patient who also had seizures improved after starting oxcarbazepine. Several cases resolved spontaneously. All authors emphasized the
tremendous fear associated with hematohidrosis and the importance of reassurance. No one appears to have died of it.
The report from Italy in CMAJ1 is typical: a
young woman with debilitating psychic
distress.
In sum, clinical reports of true hematohidrosis persist at a steady and possibly rising
rate. This collection of well-documented
observations commands respect and
acceptance. But why — with all this evidence — do we still harbour doubts about
its existence? Other rare conditions are not
viewed with similar skepticism. Ironically,
for an increasingly secular world, the longstanding association of hematohidrosis
with religious mystery may make its existence harder to accept. It seems that
humans do sweat blood, albeit far less often
literally than metaphorically.
Jacalyn Duffin MD PhD
Hannah Chair of the History of Medicine,
Queen’s University, Kingston, Ont.
References
1. Maglie R, Caproni M. A case of blood sweating:
hematohidrosis syndrome. CMAJ 2017;189:
E1314.
2. Kaposi M. Pathology and treatment of diseases of the
skin: for practitioners and students. Johnston JC,
translator. London (UK): Bailliere. Tindall and Cox;
1895:118, 409.
3. Holoubek JE, Holoubek AB. Blood, sweat and fear. A
classification of hematidrosis. J Med 1996;27:115-33.
4. Stolberg M. Sweat: learned concepts and popular
perceptions, 1500–1800. In: Horstmanshoff M, King
H, Zittel C, editors. Blood, sweat and tears: The
changing concepts of physiology from antiquity into
early modern Europe. Leiden-Boston: Brill;
2012:503-22 (esp. 509).
5. Debru A. La sueur des corps: le De sudore de Théophraste face à la tradition médicale. In: Fortenbaugh WW, Wöhrle G, editors. On the opuscula of
Theophrastus. Stuttgart (Germany): Franz Steiner
Verlag; 2002:163-74 (esp. 168n23).
6. Bynum CW. Wonderful blood: Theology and Practice
in Late Medieval Northern Germany and Beyond. Philadelphia: University of Pennsylvania Press; 2007.
7. Spörlin G. Letter [1627], in Wilhelm Fabricius Hildanus. In: Opera quæ extant omni. Frankfurt (Germany): Johannis Beyeri; 1646;601.
8. Ledelius S. in Manget JJ. Bibliotheca medico-practica sive rerum medicinarum thesaurus etc. Vol. 4.
Geneva: Chouet and Ritter; 1697;592.
9. de la Tourette GG. Traité clinique et thérapeutique
de l’hystérie d’après l’enseignement de la
Salpêtrière. In: Part 1: Hystérie normale ou interparoxystique. Paris (France): Plon; 1891;438-58 (esp.
446-7).
10. Pooley JH. Bloody sweat. Popular Science Monthly
1885;26:357-65.
11. Ratnoff OD. Psychogenic purpura (autoerythrocyte
sensitization): an unsolved dilemma. Am J Med
1989;87:16N-21N.
12. Chambers TK. Clinical Lecture on a case of “bloody
sweat.” Given at St. Mary’s Hospital, Feb. 9th, 1861.
Lancet 1861;77:207-9. (esp. 208).
This article was solicited and has been peer
reviewed.
Additional resources are available in Appendix 3
(available at www.cmaj.ca/lookup/suppl/
doi:10.1503/cmaj.170756/-/DC1).
Acknowledgements: The author thanks Professors Paul Potter, Beate Gundert and Vivian Nutton for their Galenic wisdom; Dr. Belle Song for
translation from Chinese; and Hissan Butt, Walton Schalick III, R.D. Wolfe and the anonymous
readers for their comments.
CMAJ | OCTOBER 23, 2017 | VOLUME 189 | ISSUE 42
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HUMANITIES
appeared in Canadian journals, although
Canadians George Adami and John McCrae
(physician poet who wrote “In Flanders
Fields”), both of McGill University, mentioned it briefly as a form of cutaneous hemorrhage in their pathology textbook. Most of
the articles were isolated case reports. The
few that were not case reports are historical, retrospective diagnoses linking hematohidrosis to Christ’s bloody sweat, the stigmata of St. Francis or Louise Lateau (1875),
or the death by accidental poisoning of
Charles IX of France, a story purveyed by
Voltaire and immortalized by Alexandre
Dumas in his novel, La Reine Margot (1845).
In discussion, several authors linked
bloody sweat to hysteria or psychic causes,
raising the question of its association with
psychogenic purpura (Gardner-Diamond
syndrome).11 Some continue to suggest
that it is factitious, or a product of malingering, especially in articles from the early
20th century.
The 42 medical articles from 1880 to
2017 appeared at an average rate of one
every three years. Of this total, however,
five appeared in 2013, four in 2014, three in
2015, four in 2016 and two in 2017 (so far).
In other words, almost half the total output from more than a century came in the
last five years. Is the incidence of this condition increasing? Is it being more frequently recognized, as other causes or
diagnoses are identified and eliminated?
Does the “need to publish” goad authors
to describe cases that they might otherwise have ignored? It seems unlikely that
anyone who witnessed such a case would
not want to write about it: as Thomas K.
Chambers wrote in 1861, “I suppose since
the invention of printing, very few examples of so strange a thing can have escaped
being put into type.”12
To revisit and update the Holoubek classification, the 28 new cases in the peerreviewed literature between 2004 and 2017
were analyzed. They came from nations on
every continent, except North America.
Twenty-four were female, four male. Most
were young, with an average age of 14.1
years for females (range 7 mo to 34 yr) and
26.5 years for the four males (9, 10, 15 and
72 yr) (Appendix 2, available at www.cmaj.
ca/lookup/suppl/doi:10.1503/cmaj.170756/-/
DC1). Many were photographed.
All experienced transient but recurring