This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
Arthritis is one of the oldest words in medicine and one of the least precise, and this atlas records it deliberately as a general class rather than a single condition, the same discipline it already applies to cancer and cardiovascular disease. The name itself, from the Greek arthron, joint, and the suffix -itis, inflammation, says only that a joint is inflamed, and says nothing about why: osteoarthritis is the mechanical wear of cartilage over time, while rheumatoid arthritis is the body's own immune system attacking joint tissue, a fundamentally different disease that happens to produce some of the same symptoms.
Ancient physicians did not distinguish between these causes. The Egyptian Ebers Papyrus, from around 1500 BCE, described a condition resembling rheumatoid arthritis, and the Hippocratic corpus, from around 400 BCE, describes joint pain and swelling; Hippocrates noted conditions resembling arthritis, sometimes referring to less severe pains distinct from gout, without otherwise sorting out the different diseases hiding under one broad description. That sorting would not begin in earnest for another twenty-two centuries.