Disease

A disease was a detrimental medical condition that was not an injury.

Description
A disease could be transmitted in various ways: injury, ingestion, inhalation, or mere contact. Some were also caused by parasites.

Creatures exposed to a disease ran the risk of becoming infected. Once infected, the disease took hold in a body that was not of strong enough constitution. After an incubation period, the disease showed its symptoms, which persisted until the host was cured of the disease or died of it.

Diseases in Society
Most people had no real medical knowledge and therefore relied first and foremost on experience when dealing with diseases, re-using methods that had helped themselves or close associates in the past, and second on the counsel of elders and the like. That said, most people had at least some shared understanding about how certain diseases were transmitted, even if they might disagree about treatment methods. There were at least two reasons for such disagreement: first, there was the aforementioned reliance on personal experience, and second, there was false information that was intentionally spread, such as by followers of Talona.

The most well-known diseases in Faerûn included the so-called Five Fevers and Three Plagues.

Plagues
On Toril, widespread plagues were mostly a problem of the past by the 14 century DR. The reason for this was that diseases turned into widespread plagues when a population had never encountered them before. Toril had a long history of interracial intermingling and even crossbreeding. People were exposed to various diseases since childhood and therefore developed immunities and, being the descendants of survivors of plagues, they also inherited immunities from their ancestors. Overall, widespread plagues were not a problem in urban areas but more in isolated rural areas.

Another reason why plagues were contained was that preventive treatment was done on an official level by the priesthood and/or rulers. This was done either through official enforcement or by secretly mixing medical substances into food and water. People who were strangers and obviously afflicted were generally killed, at least in frontier regions. On the Sea of Fallen Stars, it was a widespread understanding that a ship carrying plague would signal this to other vessels by smearing blood or red paint on the sails. In response, other vessels would provide clerical healing if available, otherwise they were advised to burn the plague ship to the waterline with fire arrows or spells.

Common Diseases
The most common or well-known diseases in Faerûn were:

Other notable diseases included:

Regional Diseases
Regional diseases included:

Unique Diseases
Notable unique diseases included:

Non-Humanoid Diseases
Diseases affecting creatures other than humanoids included: