Numerous theories have been proposed for the causes of dancing mania, and it remains unclear whether it was a real illness or a social phenomenon. One of the most prominent theories is that victims suffered from ergot poisoning, which was known as St Anthony's Fire in the Middle Ages. During floods and damp periods, ergots were able to grow and affect rye and other crops. Ergotism can cause hallucinations, but cannot account for the other strange behaviour most commonly identified with dancing mania. Many sources discuss how dancing mania, and tarantism, may have simply been the result of stress and tension caused by natural disasters around the time, such as plagues and floods...people may have danced to relieve themselves of the stress and poverty of the day, and in doing so, attempted to become ecstatic and see visions. Sources agree that dancing mania was one of the earliest forms of mass hysteria, and describe it as a "psychic epidemic", with numerous explanations that might account for the behaviour of the dancers. Another popular theory is that the outbreaks were all staged, and the appearance of strange behaviour was down to its unfamiliarity. Religious cults may have been acting out well-organised dances, in accordance with ancient Greek and Roman rituals. Despite being banned at the time, these rituals could be performed under the guise of uncontrollable dancing mania.

Justus Friedrich Carl Hecker was a German physician and medical writer, whose research focused on the history of epidemics, in a broad sense of the term that included pandemics like the Black Death as well as the group of social phenomena known as dancing mania. The Epidemics of the Middle Ages comprises three of his works -- The Black Death, The Dancing Mania, and The Sweating Sickness -- translated by the English epidemiologist Benjamin Guy Babington. Despite what the name of the book may suggest, the events it describes are not limited to the Middle Ages. The Black Death recounts the history of the bubonic plague in Europe, with particular attention to its cultural ramifications, such as the Flagellant movement and persecution of the Jews. The Dancing Mania describes mysterious social phenomena that occurred mainly in Europe between the 14th and 17th centuries, in which groups of people engaged in apparently uncontrollable dancing. The nature of the dancing mania continues to be a subject of debate, and Hecker's book remains one of its most comprehensive descriptions. The Sweating Sickness was a series of epidemics that struck England and later continental Europe during the 15th and 16th centuries. Hecker's account pays particular attention to its impact on political history. Hecker's books were written before the germ theory of disease became widely accepted. While his accounts of epidemics are based on critical examination of historical evidence, modern readers are likely to disagree not only with his epidemiological theories, but also with his assessments of the evidence itself. These disagreements can provide a striking illustration of how the prevailing views of one's time may affect one's judgements about credibility of primary sources. The audiobook includes appendices which contain source materials, including a 1552 treatise by the English physician John Caius and examples of music as well as short texts in Latin, German, and the early modern German dialect of Cologne.