Originally documented by the ancient Roman scholar Celsus in his work De medicina, these words describe the four overt signs of inflammation around an infected wound or mucous membrane: swelling, redness, pain, and heat. A fifth sign, fluor, meaning 'secretion,' is sometimes added to this list, at the recommendation of modern pathologist M.J. Mitchinson.
Broadly, these symptoms (with "heat" including fever and "swelling" including glandular and lymph node inflammation as possibilities) can be expected to occur to some extent in response to nearly anything whatsoever going wrong in a human body, since the inflammatory response tends to "overreact" rather than "underreact" to physical trauma or immunocompromise of any sort. As such, they are usually only useful diagnostic tools in terms of confirming that something is wrong, and they are unlikely to indicate what is wrong.
Iron Noder 2018, 11/30