The Phlegmpire Strikes Back: Deadly Star Wars Diseases

There's more to fear than space slugs and rancors in a galaxy far, far away.

Got a bad cold and don’t know what caused it? Sore throat come out of nowhere? Here are seven interesting diseases from the Star Wars galaxy that just might explain…

The Star Wars galaxy is place of awe and wonder. From the lush and magical forests of Endor to the sweeping ice plains of Hoth, the beauty of a Bespin sunset to the glamor of a Coruscant skyline, the galaxy is packed with amazing sights, sounds, and species. But it’s also a dangerous place. Asteroid fields, rancors, the dark side, cyborgs, dianogas, giant green carnivorous rabbits…

That being said, not all dangers are immediately visible. Some of the most lethal adversaries a traveler trying to see the galaxy on just 30 dataries a day can encounter are microscopic, but no less deadly than a ravenous wampa or an angry acklay. In a galaxy holding 180 billion life sustaining planets and a galactic ecosystem growing more complex by the day, first contact situations occur constantly. And — unless there’s a unified galactic inoculation service that the Republic kept quiet all these centuries — it’s highly likely that disparate species would be innocently passing viruses and diseases on to each other all the time. In short, a sneeze could cause as much destruction as a Star Destroyer, so let’s take a look at just seven of the deadliest diseases the galaxy has to offer, from both Legends stories and within canon.

Brainrot Plague

Brainrot PlagueIf drinking 30 flagons of Flameout isn’t enough to rot your brain then you can always contract Brainrot Plague. This horrific airborne virus targets humanoids and cephalopoids, attacking the central nervous system causing nausea, sweats, communication breakdown and — if untreated by immunization — a swift death. Used by the Separatists during the Clone Wars as a form of germ warfare, Brainrot Plague (otherwise known as Loedorvian Brain Plague) wiped out the entire humanoid population of the Weemell sector, leaving it uninhabitable. It even struck the Manarai Heights area of Coruscant, leading to public service announcements and awareness campaigns by the Coruscant Health Office.
And it comes in three different variations — A, B, and C — so if it doesn’t get you the first time there are always two other types lurking around to get you later.

Vira 606

Germ and chemical warfare has been a common and despicable weapon for military forces through the ages but for the agents of the Imperial Security Bureau, such moral concerns were an irrelevance. Vira 606 was synthetically developed to take down its enemies and was fatal without exception. Only a precise course of injections could counter its effects and as a means of holding sway over an enemy it was devastatingly effective. Imagine, holding the serum to keep a killer disease at bay and the power it would give one individual over another.

Hibernation Sickness

Hibernation Sickness

Bad enough that you’ve been betrayed by your so-called friend. Bad enough that your girlfriend’s dad turned you into a coffee table. Picture the shock of coming back to life a year later in Jabba the Hutt’s court, confused and afraid, weak, blind, and aching. That’s hibernation sickness, the result of a process described as a constant, waking last breath. No wonder Han Solo was so befuddled once he’d been freed by an undercover Princess Leia.

Occasionally the effects of hibernation sickness lead to death but more often than not they wane and retreat after a day or so. Potentially the victim could be held for weeks, months, even years in such a frozen state and as such the effects of the hibernation sickness would be worse still. Not strictly a disease, more a side-effect of a traumatic process, but it certainly reminds us to not cross your future in-laws.

Mon Calamari Nerveshock

Mon Calamari

Being a largely aquatic species, Mon Calamari children had extra levels of danger to face when growing up. No, I’m not talking about peeing in the pool, I mean a deadly virus called Mon Calamari Nerveshock. Fatal if not immunized against, the disease would lay dormant for years before exploding inside its host and attacking the nervous system. By this time it was already too late to save the patient and so a process of immunization was started to inoculate Mon Cal youngsters and bypass the diseases terrible effects.

Quannot’s Syndrome

Children of the Jedi Cover

The novel Children of the Jedi holds many secrets and the devastating Quannot’s Syndrome is one of them. A debilitating disease, this causes so much excruciating pain to its victim that only large doses of the painkiller perigen can hold it at bay, but no medical intervention can cure it. In the novel, the trainee Jedi Nichos Marr is stricken by the disease and, unable to cure him, his lover Cray Mingla attempts and fails to transfer his consciousness to a droid body, proving that even in the Star wars galaxy there are some things you quan do and some things you quannot…

Eerie Coulee Disorder


In a galaxy serviced by automatons for millennia the thought that people might be afraid of droids may seem somewhat akin to having a fear of fridges. But as technology developed and grew, some droids were designed to be more and more human-like in appearance. This in turn led to the discovery of Eerie Coulee Disorder (or ECD), whereby humanoid species felt wary and uncomfortable around such machines.

Anyone with ECD meeting Prince Xizor’s Human Replica Droid Guri would almost certainly have felt more than a small sense of apprehension, and it’s likely one of the reasons why droids were largely designed to be more functional and practical in their design and less smooth and organic.

Rakghoul Plague

Plague At Work

This one might be the most terrifying of the seven. A mere bite or scratch from an infected host and within a span of six to 48 hours you turn into a Rakghoul, a monstrous, mindless creature brought about by a Sith engineered disease concocted by the ancient Sith Lord Lord Karness Muur. Attempting to cheat death as all Sith do, Muur transferred his will and power into the Muur Talisman, an amulet which could transform nearby sentient beings into Rakghouls and in turn those Rakghouls could infect and turn almost any other sentient being (other than Force-sensitives). It’s another disease with two strains — the Bozan strain and the Hirano strain — and it had no cure. Surviving from ancient Sith times through to the era of Cade Skywalker, this was as easily transferred as a firm handshake and was carried by every Rakghoul in existence. And yes, it caused as much death and destruction as a Star Destroyer.

And there you have it, just a few examples of the endless plagues, diseases, afflictions, and illnesses that could befall you while traversing the galaxy. No wonder such a huge percentage of the galaxy’s inhabitants were much like you and me, staying on one world for the whole of their lives, dreaming of adventures beyond the stars but never taking that step. Besides, we’ve got more than enough things to worry about without having to think about the Blue Shadow Virus and the Cardooine Chills.

Mark Newbold is the co-owner of and has been a contributor to Star Wars Insider since 2006. He also is the co-host alongside James Burns of the Radio 1138 podcast.