What is Bubonic plague?
{{Use dmy dates|date=May 2020}} {{Infobox disease | Name = Bubonic plague | Image = Plague -buboes.jpg | Caption = An inguinal 'bubo' on the upper thigh of person infected with bubonic plague. Swollen [[Lymphatic system|lymph]] glands (''buboes'') often occur in the neck, armpit and groin (''inguinal'') regions of plague victims | ICD10 = {{ICD10|A|20|0|a|00}} | ICD9 = {{ICD9|020.0}} | DiseasesDB = 14226 | eMedicineSubj = | eMedicineTopic = | MeshName = | MeshNumber = D010930 | MedlinePlus = 000596 }} '''Bubonic plague''' is the best-known form of the disease [[plague]] caused by the [[bacterium]] ''[[Yersinia pestis]]''. The name ''bubonic plague'' is specific for this form of the disease, which enters through the skin, and travels through the [[lymphatic system]]. The plague was spread by [[flea]]s on [[rats]]. This method of spreading disease is called a [[zoonosis]]. If the disease is left untreated, it kills about half its victims in three to seven days. The bubonic plague was the disease that caused the [[Black Death]], which killed tens of millions of people in Europe, in the [[Middle Ages]].<ref>{{cite web|url=http://news.nationalgeographic.com/news/2004/03/0310_040310_blackdeath.html|title=Bubonic plague traced to Ancient Egypt |first=Cameron|last=Walker|publisher=National Geographic News|date=10 March 2004|accessdate=2 April 2009}}</ref> [[Symptom]]s of this disease include [[cough]]ing, [[fever]], and black spots on the [[skin]]. == Different kinds of the same disease == There are different kinds of Bubonic plague. The most common form of the disease is spread by a certain kind of [[flea]], that lives on [[rat]]s. Then there is an [[incubation period]] which can last from a few hours to about seven days. === Septicemic plague === [[Sepsis]] happens when the bacterium enters the [[blood]] and makes it form tiny clots. === Pneumonic plague === This happens when the bacterium can enter the lungs. About 95% of all people with