A Guide to Making Up Diseases (as Explained by a Biologist)
So listen up y’all, nothing drives me crazier as both a writer and a scientist than seeing alien diseases that make no fuckin’ sense in a human body.
If you’re talking about alien diseases in a non-human character, you can ignore all this.
But as far as alien diseases in humans go, please remember:
DISEASE SYMPTOMS ARE AN IMMUNE RESPONSE.
Fever? A response to help your immune cells function faster and more efficiently to destroy invaders.
Sore/scratchy throat? An immune response. Diseases that latch onto the epithelium of the throat (the common cold, the flu) replicate there, and your body is like “uh no fuckin’ thanks” and starts to slough off those cells in order to stop the replication of new virus in its tracks. So when it feels like your throat is dying? guess what it literally is. And the white spots you see with more severe bacterial infections are pus accumulation, which is basically dead white blood cells, and the pus is a nice and disgusting way of getting that shit outta here.
(No one really knows why soreness and malaise happens, but some scientists guess that it’s a byproduct of immune response, and others suspect that it’s your body’s way of telling you to take it easy)
headache? usually sinus pressure (or dehydration, which isn’t an immune response but causes headaches by reducing blood volume and causing a general ruckus in your body, can be an unfortunate side effect of a fever) caused by mucous which is an immune response to flush that nasty viral shit outta your face.
Rashes? an inflammatory response. Your lymphocytes see a thing they don’t like and they’re like “hEY NOW” and release a bunch of chemicals that tell the cells that are supposed to kill it to come do that. Those chemicals cause inflammation, which causes redness, heat, and swelling. They itch because histamine is a bitch.
fatigue? your body is doing a lot–give it a break!
here is a fact:
during the Spanish 1918 Plague, a very strange age group succumbed to the illness. The very young and very old were fine, but people who were seemingly healthy and in the prime of life (young adults) did not survive. This is because that virus triggered an immune response called a cytokine storm, which basically killed everything in sight and caused horrific symptoms like tissue death, vasodilation and bleeding–basically a MASSIVE inflammatory response that lead to organ damage and death. Those with the strongest immune systems took the worst beating by their own immune responses, while those with weaker immune systems were fine.
So when you’re thinking of an alien disease, think through the immune response.
Where does this virus attack? Look up viruses that also attack there and understand what the immune system would do about it.
Understand symptoms that usually travel together–joint pain and fever, for example.
So please, please: no purple and green spotted diseases. No diseases that cause glamorous fainting spells and nothing else. No mystical eye-color/hair-color changing diseases. If you want these things to happen, use magic or some shit or alien physiology, but when it’s humans, it doesn’t make any fuckin’ sense.
This has been a rant and I apologize for that.