Diagnosing Westeros: The diseases of Game of Thrones

By Melissa Sammy, MDLinx
Published May 10, 2019

Key Takeaways

HBO’s popular, award-winning series Game of Thrones has become a cultural phenomenon. Millions of viewers across the globe tune in every week to watch the fantasy drama full of magic, political intrigue, and multilayered storylines unfold. The season 8 premiere alone garnered a series record of 17.4 million viewers across all cable and streaming platforms.

Take away the dragons, divine resurrections, and warring undead, however, and you’ll find Westeros not dissimilar to real-world Medieval Europe. Indeed, author George R.R. Martin drew inspiration from certain historical events, including the English Wars of the Roses, when penning his epic A Song of Ice and Fire series, on which the television show is based. From knights and lords to war and poverty, both the novels and television show capture many of the realities of life in the Middle Ages—except for one crucial aspect: disease.

In a show that takes great pains to mirror the trials and tribulations of both high- and low-born medieval life, the prevalence of illness is surprisingly absent from this picture, save for a notable few. Let’s take a look at the real-world inspirations and counterparts behind some of these diseases in the world of Game of Thrones, as well as the real-world health conditions that would literally plague Westeros.

The science behind fiction


Highly infectious and painful, greyscale is a skin disease transmitted through direct contact with an infected individual or via contact with unsterilized objects that have been handled by the infected. The disease, usually fatal, is characterized by the skin’s progressive calcification that eventually resembles grey reptilian scales or mottled grey stone in the more severe stages.

During its mid-to-late stages, the infection will spread across the individual’s skin from head to toe, and in its final stages, to the body’s internal organs, calcifying them as well. As the brain deteriorates, those infected devolve into a feral state. Because of their contagious and violent nature, greyscale victims—often referred to as Stone Men—are exiled from society to live under quarantine until death.

Princess Shireen Baratheon and Ser Jorah Mormont are the only two known survivors of greyscale—the latter of whom made a full recovery upon a dangerous pioneer surgical procedure that involved flaying of the infected skin and administration of a topical salve to the newly exposed flesh. Due to the highly contagious nature of the disease and the risk of accidental penetration and exsanguination, few maesters have attempted to cure greyscale, and only one has succeeded.

Although fictional, greyscale shares several characteristics with real-life diseases, notably epidermodysplasia verruciformis (EV), also known as “tree man syndrome,” and leprosy. Similar to greyscale, EV is a skin disorder characterized by chronic infection—in this case, human papillomavirus—that results in polymorphous cutaneous lesions with a texture similar to wood or stone. The prognosis for EV, however, is much more favorable than that of greyscale, with management of the disease consisting of cryotherapy, topical imiquimod and 5-fluorouracil, systemic retinoids, interferon alpha, 5-aminolevulinic acid photodynamic therapy, and/or surgical excision.

From a historical standpoint, greyscale closely parallels leprosy—a chronic, contagious, and painful infectious disease that primarily affects the skin. Like those infected with greyscale, people with leprosy can become disfigured, are often stigmatized, and were frequently isolated from society. In an interview, author George R.R. Martin likened the shuffling and quarantine of Stone Men in Old Valyria to that of a leper colony.

Leprosy can take years to progress to its final stages, often resulting in disability due to nerve damage and pain, in a manner similar to greyscale. Unlike greyscale, however, leprosy is now completely curable with generally noninvasive multidrug therapy involving antibiotics. Of note, current treatment cannot reverse nerve damage or physical disfiguration that may have occurred pre-diagnosis.

The Pale Mare

Although not depicted on-screen, the “pale mare” is a well-known inflammatory disease in the world of Game of Thrones. Detailed in the novels of A Song of Ice and Fire, the pale mare is closely associated with conflict and wartime illnesses. For instance, reports of the pale mare are mentioned in A Clash of Kings following the riot of King’s Landing during the War of the Five Kings, which correspond to similar events that take place during the second season of the television series, and in A Storm of Swords during Daenerys Targaryen’s siege of Meereen, which correspond to events from the fourth season. In A Dance of Dragons, Ser Barristan Selmy explains to Daenerys that the disease has been the “bane of every army since the Dawn Age,” warning that it can “destroy whole armies when left to spread unchecked.”

Its symptoms include fever, intestinal hemorrhages, and diarrhea that can all lead to death. Across the Narrow Sea in Westeros, it is known by another name: the bloody flux. Sound familiar? It should.

Historically known as the bloody flux or simply “the flux,” dysentery is the pale mare’s real-life counterpart. Although the pale mare’s etiology is unclear, it’s probably safe to assume that it mirrors that of dysentery, with some characters in the novels warning others to avoid drinking from water sources that may be contaminated.

This highly infectious gastrointestinal disorder comes in two forms: bacillary dysentery, which is caused by shigella bacteria, and amoebic dysentery, which is caused by the single-cell parasite Entamoeba histolytica. The disease is often spread through contaminated water or food. Like the pale mare, symptoms of dysentery include bloody diarrhea, painful stomach cramps, nausea, vomiting, and fever.

A bit more straightforward than in the novels, which suggest treatment of the pale mare by means of rehydration with clean water and good hygiene, treatment of dysentery can include antidiarrheal medications, pain- and fever-reducing agents, and increased fluid intake. It will usually resolve on its own in 3-7 days. Antibiotic treatment, however, may be necessary for more severe cases.

If Westeros were historically accurate

Now that we’ve ferreted out some of the real-world diseases that may have inspired the fictional ones in Game of Thrones, let’s take a look at real-world health conditions that should be rampant in Westeros.


If you watch Game of Thrones, you know to expect two things: lots of violence and lots of sex. Indeed, several episodes have featured various characters—notably King Robert Baratheon, Tyrion Lannister, and Prince Oberyn Martell of Dorne—engaging in sex with numerous partners, especially prostitutes. And while Moon Tea is often given to sexually active women on the show and in the books as an abortifacient, there is little-to-no mention of the existence of sexually transmitted infections or diseases, much less the use of protection.

Because Game of Thrones is rooted in medieval history, syphilis—which swept through Europe during the 15th century—would likely be the most prevalent sexually transmitted infection in Westeros, given the regularity of brothels and opportunity for transmission.

Syphilis is contracted via direct contact with a syphilis sore, usually during oral, vaginal, or anal intercourse. Symptoms generally include painless sores on the genitals, rectum, or mouth in the first stage; rash, swollen lymph nodes, and fever in the second stage; and damage to the brain, nerves, eyes, or heart in the final stage.

On a positive note, syphilis can now be cured with antibiotic treatment. Though, in the medieval setting, ye olde cures for sexually transmitted infections likely would have included leeching and urethral irrigation, among others.

Necrotizing fasciitis


Viewers have seen many horrific deaths on Game of Thrones—from disembowelment and beheading to burning and skull-crushing. However, fatal medical outcomes due to prolonged wound exposure, subpar sanitary conditions, and subsequent infection—all of which have been historically common during wartime—have yet to be depicted on-screen. Deaths attributable to necrotizing fasciitis, or “flesh-eating disease,” for example, would probably have been prevalent in Westeros—a land rife with war but devoid of modern antibiotic treatment.

Although rare, most outbreaks occur in war-torn regions and are restricted to military hospitals. For example, necrotizing fasciitis occurred in more than 2,500 soldiers during the Civil War. This gruesome, lethal infectious disease destroys tissue under the skin, spreads rapidly in the body, and can lead to death.

Symptoms include red or purple swollen skin in the affected area; ulcers, blisters, or black spots on the skin; pus oozing from the infected area; diarrhea and vomiting; and severe pain, fever, and fatigue. According to the CDC, infection tends to be contracted through breaks in the skin, including cuts and scrapes, burns, insect bites, and puncture and surgical wounds. Treatment includes intravenous antibiotics and surgical excision of the dead tissue upon prompt diagnosis.


Given the sea-faring culture of the Ironborn, whose way of life is rooted in piracy and raiding, it’s no far leap to assume that the real-world disease of scurvy, or its fictional equivalent, would plague the leagues of reaving sailors.

Scurvy is characterized by vitamin C deficiency, and symptoms include poor wound healing, bruising, weakness, fatigue, bleeding gums, and loss of teeth. Left unchecked, scurvy can lead to a compromised immune system that may allow for opportunistic infection, serious complications, and death. From the late 15th century to the mid-19th century, scurvy was responsible for the death of over 2 million sailors, and claimed the lives of more seamen than storms, shipwrecks, and naval skirmishes combined.

The treatment for scurvy, however, is quite simple: vitamin C replenishment, either through supplements or consumption of fruits (especially citrus) and vegetables high in vitamin C.

The Black Death

Several character favorites on Game of Thrones have shuffled off their mortal coils in the most epic of ways. But consider that many would likely have succumbed to plague-like illness vs mortal wounds sustained from combat in the real-world setting, specifically the bubonic plague—or “Black Death”—which wiped out about one-third of Europe’s population in the mid-14th century. Also known as the “Great Pestilence,” this disease is caused by Yersinia pestis, and is often spread through the bite of infected fleas and rats. Symptoms of bubonic plague include fever, headaches, chills, weakness, aches and pains, diarrhea, vomiting, and one or more tender, painful lymph nodes that usually result from the bite of an infected flea.

In addition to scurvy, the Ironborn would doubtlessly have suffered mass casualties from the Black Death, given that rats were particularly at home aboard ships in the Middle Ages. The poor smallfolk who reside in the slums of Flea Bottom in King’s Landing would also have presumably been victims of the Black Death in light of their crowded, unsanitary living conditions. And considering the most recent events on the series—in which they have all been shepherded to the “safety” of the Red Keep—the opportunity for transmission would be significant, with the potential to be as swift and catastrophic as wildfire.

In fact, similar conditions led to the plague-like epidemic known as the Great Spring Sickness, the events of which are detailed in the A Song of Ice and Fire novellas, The Sworn Sword and The Mystery Knight. The disease killed tens of thousands across the Seven Kingdoms. Although the exact cause of the epidemic remains ambiguous, the destruction of the Great Spring Sickness was able to be staunched upon burning the bodies of infected decedents. 

Today, the bubonic plague is treatable with commonly available antibiotics. During the Middle Ages however, the outlook was far more grim, since there was no reasonable understanding of the disease’s etiology. Treatments, therefore, consisted of less sophisticated techniques, including bloodletting, boil-lancing, drinking vinegar, and various supernatural practices such as burning aromatic herbs and bathing in rosewater. Needless to say, these therapeutic options had little impact on curbing the plague’s death toll in the 1300s, and would likely have the same negligible effect on the Westerosi population.

Indeed, although the maesters of the Seven Kingdoms are skilled in the healings arts, their knowledge of medical science is not very advanced. For example, wounds are often cleaned with boiling wine, leeches are used to drain bad blood, and vinegar is used as a disinfecting agent for surgical instruments. Furthermore, because their services are costly and, thus, usually reserved for the gentry, the odds of the less wealthy commoners being afflicted with, spreading, and succumbing to any plague-like illness remains significant.

Diseases (or lack thereof) aside, Game of Thrones is a truly fantastic series that balances the thrill of the supernatural against heart-rending human narratives. If you haven't seen it, give it a try. However, a word of caution: Dying from a broken heart is real, so be careful when you watch the show. Don't get too attached to your favorite characters, lest you lose your head.

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