The plague produced some of the most visually horrifying symptoms of any disease in human history. Depending on which form a person contracted, the visible signs ranged from massive swollen lumps in the groin and armpits to blackened, dying skin on the fingers, toes, and nose. The name “Black Death” itself likely came from the dark discoloration that spread across victims’ bodies in advanced stages of the illness.
The Buboes: Swollen Lumps Under the Skin
The most recognizable sign of bubonic plague was the bubo, a painfully swollen lymph node that appeared in the groin, armpit, or neck. These swellings grew rapidly after infection, sometimes reaching the size of an egg or apple within just a day or two. Giovanni Boccaccio, the Italian writer who survived the 1348 outbreak in Florence, described them as “certain swellings in the groin or armpit, some of which were egg-shaped whilst others were roughly the size of the common apple.” That puts the largest buboes at roughly 7 to 10 centimeters across.
The skin over a bubo became stretched tight, shiny, and discolored, shifting from red to a deep purple as blood pooled beneath the surface. The lumps were excruciatingly tender. Some eventually burst open and drained foul-smelling pus, which was actually considered a hopeful sign, since patients whose buboes ruptured had a slightly better chance of surviving. Those whose buboes remained hard and sealed often deteriorated quickly.
The groin was the most common location, likely because flea bites tended to occur on the lower legs, and the bacteria traveled to the nearest lymph nodes first. Armpit buboes pointed to bites on the arms or torso, while neck buboes suggested bites on the head or upper body.
Dark Spots and Skin Discoloration
Beyond the buboes, victims often developed dark blotches across their skin. Boccaccio noted that one character in his Decameron was found with “his face and body already covered with swellings and dark splotches.” These patches, sometimes called “tokens” in later English outbreaks, appeared as purplish or black marks ranging from small spots to large irregular blotches. They resulted from bleeding beneath the skin as the infection damaged blood vessels.
The splotches could appear anywhere on the body and were widely understood as a death sentence. In medieval and early modern accounts, the appearance of dark tokens on the skin was the moment when families and caregivers often abandoned hope. The marks indicated that the bacteria had entered the bloodstream and was destroying tissue from the inside.
Blackened Extremities in Septicemic Plague
The most gruesome visual feature of plague came from its septicemic form, where the bacteria overwhelmed the bloodstream directly. According to the CDC, “skin and other tissues may turn black and die, especially on fingers, toes, and the nose.” This blackening was actual gangrene. The bacteria triggered widespread blood clotting in small vessels, cutting off circulation to the extremities. Fingers, toes, ears, and the tip of the nose turned dark purple, then black, and the tissue died while the person was still alive.
This is almost certainly the origin of the name “Black Death,” though historians have debated other explanations over the centuries. The visual reality of a person whose hands and face were turning black would have been unforgettable to anyone who witnessed it. Septicemic plague could kill within a day of the first symptoms, sometimes before buboes even had time to form, making it the deadliest and most sudden version of the disease.
Bloody Cough in Pneumonic Plague
When plague infected the lungs, it produced pneumonic plague, the rarest but most contagious form. The defining visible symptom was a cough producing blood-stained sputum. Victims struggled to breathe, gasped for air, and coughed up frothy, bright red or dark mucus. The WHO’s clinical criteria for suspected pneumonic plague specifically include “cough with blood-stained sputum, chest pain, difficulty in breathing.”
Boccaccio described victims who “simply lay there gasping for breath and perspiring all over, and shortly thereafter gave up the ghost.” The speed of pneumonic plague was terrifying. A person could be healthy in the morning, coughing blood by evening, and dead within 24 to 48 hours. Unlike bubonic plague, which required flea bites to spread, pneumonic plague passed directly from person to person through respiratory droplets, making it far more dangerous in crowded conditions.
The Full Picture of a Plague Victim
Putting all the symptoms together, a person in the advanced stages of plague presented a deeply disturbing sight. The disease typically began with sudden high fever, chills, and extreme exhaustion, leaving victims drenched in sweat and barely able to move. Within hours to days, depending on the form, the visible signs escalated: swollen, discolored lumps bulging from the groin or neck; dark purple and black patches spreading across the torso and limbs; blackened fingertips and nose; bloody saliva and labored breathing. The smell was also notable. Contemporary accounts frequently mention the terrible odor of plague victims, from the pus draining from burst buboes to the general decay of dying tissue.
Modern plague cases still look much the same. The bacterium responsible, Yersinia pestis, hasn’t changed significantly, and without prompt antibiotic treatment, the progression follows the same pattern described by Boccaccio nearly 700 years ago. About seven cases occur in the United States each year, mostly in the rural Southwest, and photos from modern clinical reports show buboes and skin necrosis that match medieval descriptions closely. The difference today is that antibiotics can stop the disease if caught early. Left untreated, bubonic plague still kills roughly half of those infected, and septicemic or pneumonic plague is nearly always fatal without intervention.