From a widespread plague to the bite of a dire rat, disease is a serious threat to common folk and adventurers alike. Diseases rarely have a limited frequency, but most have a lengthy onset time. This onset time can also be variable. Most diseases can be cured by a number of consecutive saving throws or by spells such as remove disease.
Note: Not everything listed here is a true "disease" as some of the below are more accurately described as infections, parasites, or other unfortunate maladies adventurers might occasionally have to cope with.
The following samples represent just some possible illnesses and diseases.