Everyday symptoms
http://www.wikiherb.info/2012/03/plants-to-reduce-fever.html
Some of the symptoms of the Black Death were everyday symptoms. There would be symptoms like vomiting and high fevers. Some victims of the illness would even get very sleepy and tired all the time.
Buboes
http://members.tripod.com/miss_hand_history/warminster/alistair.htm
Buboes are painful swelling of the lymph nodes. The lymph nodes are located in the neck, legs, groin and armpits. They would turn red then progress to dark purple or even black. The buboes would soon pop and ooze blood and puss.
Messing with your mind
http://angryjogger.com/marathon-tapering-blues-ive-put-on-4-5lbs-of-weight-ever-since-entering-the-3-week-long-tapering-phase-of-my-program-i-need-tips-andor-advice.html
The Black Death got into the minds of the victims stricken of the illness, so to speak. People who had the disease would be mentally unstable and basically go crazy. Delirium is where you go crazy and that's what they had.