The Black Death Defined

Learn the Causes and Symptoms

Plague-Infected Flea
A flea infected with plague. Public Domain; Courtesy National Institute of Allergies and Infectious Diseases

The plague is known as a rare but serious bacterial infection that can be deadly. Often referred to as the black plague or black death, the plague was first introduced in Europe by the sea in 1347 after a trip in the Black Sea. Sailors on the ships were either dead, ill, or overcome with fever and not able to eat food. This illness caused black boils and oozing blood and pus which killed more than 20 million Europeans.


Symptoms of Black Plague

This contagious disease caused chills, aches, vomiting and even death amongst the healthiest people. It is understood today that the plague was caused by a bacillus germ, Yersina pestis. While it could be transferred to people in the air, it also got through by bite, fleas, and rats. Due to better hygiene practices in cities, the black plague is an extremely rare disease in modern day society.

Back in the day, it started with a headache and then quickly turned into chills and fever, which left people exhausted. Many also experienced nausea, vomiting, back pain, and soreness in their arms and legs. Often, swellings would appear which consisted of hard, painful, and burning lumps on the neck, under the arms, and on inner thighs. Soon, these swellings grew to the size of an orange and turned black, split open, and began to ooze pus and blood.

Lumps and swellings would cause internal bleeding, which led to blood in the urine, blood in the stool, and blood puddling under the skin.

This resulted in black boils and spots all over the body. Everything that came out of the body smelled revolting, and people would suffer great pain before death, which could come as quickly as a week after contracting the disease.

4 Types of Plague

The swellings, called buboes, were the victim's lymph nodes, and they gave the Bubonic Plague its name.

The bubonic form of the disease was only one manifestation of the horrible pandemic that swept Europe in the 1340s. Another form was the Pneumonic Plague. The victims of Pneumonic Plague had no buboes, but they suffered severe chest pains, sweated heavily, and coughed up blood. Virtually no one survived the pneumonic form.

The third manifestation was Septicemic Plague. This sickness would befall when the contagion poisoned the victim's bloodstream. Victims of Septicemic Plague died the most swiftly, often before any notable symptoms had a chance to develop. Another form, Enteric Plague, attacked the victim's digestive system, but it too killed the patient too swiftly for diagnosis of any kind.

Medieval Europeans had no way of knowing any of this. The causes of plague were not discovered until the late nineteenth century.

The Transmission of Plague

Plague is carried by rodents like rats and squirrels, but it is transmitted to humans by the fleas who live on them. A flea, having ingested plague-infected blood from its host, can live for as much as a month away from that host before he needs to find another warm body to live on. When a blood-engorged flea attempts to draw blood from another victim, it invariably injects into that victim some of the blood already within it.

If the injected blood contains the bacterium yersinia pestis, the result is the Bubonic Plague. Fleas were such a part of everyday life that no one noticed them much. In this invisible manner, the plague spread from rat to human and to cat and dog, as well.

Pneumonic plague is airborne. It is contracted by breathing the infected water droplets breathed (or coughed) out by a victim of the disease. The pneumonic form was much more virulent and spread much more quickly and just as invisibly.

Plague is occasionally transmitted by direct contact with a carrier through open sores or cuts, directly into the bloodstream. This could result in any form of the plague except pneumonia, although it is likely that such incidents most often resulted in the septicemic variety. The septicemic and enteric forms of the plague killed most quickly of all, and probably accounted for the stories of individuals going to bed apparently healthy and never waking up.

People died so swiftly and in such high numbers that burial pits were dug, filled to overflowing, and abandoned; bodies, sometimes still living, were shut up in houses which were then burned to the ground, and corpses were left where they died in the streets.

Source: History Medren, Melissa Snell, 1998-2017