This blog is to help people with medical stuff, whether they be a student, writer, or whatever.
You can ask me anything you want, but I'm probably most knowledgeable about general medical questions, EMS, chemistry, and biology. If I don't know the answer to your question, I can probably find it, or at least point you in the right direction.
I've tagged the hell out of every post, so I hope you will be able to find things easily. The main topics are listed below, and then the specific part I'm talking about (hand, eyes, spleen, etc.) is tagged as well. "Writing reference" is also used when I specifically give tips about writing about medical stuff, though you could use any of this stuff to write if you wanted to.
If you ever write something using the info on this page, I would love to read it, honestly. Not to critique it, just to see what people can do with the bland medical info I put out :)
Also, I am human and I make mistakes. If you see anything in a post that you feel is inaccurate, please shoot me a DM to let me know. Also, if you want a source for something, I always have those available (though sometimes these are textbooks that not everyone has access to).
so many of my posts have gotten flagged for mature content over the past few months. i don't even know if you guys can still see some of them?? i don't know how this works
hi gang. reminder that we are some of the best sweaters in the animal kingdom (second only to equines) allowing us to stay cool and keep moving in hot weather. we have 10 times the density of sweat glands compared to other great apes.
we are ALSO insanely good at smelling rain (specifically geosmin, found in the soil and activated by rain) with the ability to smell 10 parts per trillion. this is speculated to have helped our ancestors survive!
we ALSO have absolutely batshit diets compared to most other animals. caffeine and chocolate are completely toxic to most animals but we can eat it without even feeling sick. even avocados are severely toxic to many animals to the point where it can be fatal to eat, but humans love it!!!
we are ALSO the best endurance runners ON EARTH out of ANY other species. we beat horses in endurance running. you know, the animals that gradually evolved away most of their toes in order to be the best runners?? yeahhh.
and to top it all off. our lifespan is unusually long for our species' weight/mass. typically, the bigger a species is, the longer its average lifespan (e.g. domestic mice live for 1-3 years, whales can live over 200) but we're very small for how long our average lifespan is. big cats like tigers live around 14-15 years, brown bears 25 years, yet here we are expected to live around 75-85 years. that is NUTS.
humans as a species are so extremely cool. it's not just our intellect that makes us amazing. we may not be the fastest or the strongest in the animal kingdom but we're super cool in many other ways. next time you sweat you can go wow!!! humans are so cool I'm able to keep moving because of my absolutely insane number of sweat glands! thank you evolution!
good lord there's a lot of vasectomy joke gifts that don't know the difference between a vasectomy and an orchiectomy.
orchi is removing of one or both testicles. a vasectomy cuts or seals the vas deferens so there's no sperm in your semen. You still have testicles, you still have testosterone, there's just no sperm in your ejaculate to make babbies with.
What's the smallest/stupidest reason for someone to need a bone marrow aspiration. Like I know the usual stuff that it says on mayo clinic, but, what would make the procedure completely unnecessary while still justifiable/able to be rationalised? My patient character doesn't have any underlying conditions or a mystery fever, my doctor character just "needs" to "help" them by doing a bone marrow exam.
Hmm...that's a tough one. Usually they're done to help diagnose problems with blood cells. So, we could give your character a problem that should probably have other testing done with that, and the doctor is just jumping the shark. This could be something like anemia (low red blood cells) or really any problem with blood cell numbers (red, white, platelets), as synthesis or maturity of these cells happens in the bone marrow. So I guess you could just have the patient bleed a lot, be pale (and other anemia symptoms), or get sick more often, and the doc is just going straight to a biopsy for some reason.
"being a human is so boring why can't I be one of the COOL animals" okay hey. I hear you. but I actually really super love being an omnivorous persistence hunting primate with a stomach capable of dissolving many literal poisons and the ability to smell geosmin (released in the soil after it rains) at five parts per trillion. I super enjoy being a bipedal terrifyingly agile mammal with some of the most efficient sweat glands in the animal kingdom. I find a lot of joy in being an endotherm with mimicry abilities that rival most other animals with vocal chords. it's sick as hell I'm having a lot of fun
humble that man. he should have to be nursed back to health my his romantic interested and accidentally throw up and pass out on them when they try to clean his wounds
Pretty famous disease right here. And it's one of two that has been declared eradicated by the WHO, so that's pretty rad. So we're gonna go through what this is, what it does, and some fun facts that you probably don't want to know. Also, THERE ARE NO PICTURES SO DONT FLAG THIS SHIT AS MATURE. It's educational...
Smallpox is caused by the variola virus, which is an Orthopoxvirus (so is horsepox, monkeypox, etc.). It's been around forever, but we got rid of it in the 70s. Initial symptoms start a few days after infection and include fever, headache, fatigue, GI issues, and muscle pain.
Within 2 weeks, you'll start to get the enanthem (small red spots) in the mouth and nose. They'll grow until they pop. Within a day or two of these lesions, you'll also get the characteristic pox. These are macules that start on the dace and spread to the trunk and limbs. What happens next depends on the specific form of smallpox.
Ordinary smallpox is about 90% of cases, in which the macules become papules, which become vesicles, which turn into pustules. It's a bunch of pus-filled blisters on your skin, basically. After two weeks, they scab up and fall off, which leaves the distinct depigmented pox scars behind. This form kills about 30% of those infected.
Modified smallpox is rare, happens in the vaccinated, and is not usually fatal.
Malignant smallpox is known for lesions that are flat and extreme fever. The lesions were described as "velvety." It was almost always fatal, about 97% so in the unvaccinated. However, it only made up about 7% of cases.
Hemorrhagic smallpox can be split into early and late types. The early type is 100% fatal in the vaccinated and unvaccinated, but the late type is only 97% fatal in the unvaccinated and 90% fatal in the vaccinated. It was referred to as "black pox" due to dark bleeding under the skin. The early form causes bleeding from the eyes and membranes, and dark patches on the skin (this is blood). Death usually occurred within a week. Sometimes people's skin would start detaching a falling off while they were fully conscious.
The late form also causes bleeding under the skin, but not as much eyeball and membrane bleeding. You can also get pustules with this type. It destroys the coagulation cascade, which means you can bleed like crazy. Most people are dead in a little over a week.
The way we countered this disease was with an intense vaccination campaign from the 50s-70s. People have been inoculating themselves against it for hundreds of years by using less severe diseases like cowpox. However, this still killed a lot of people. The modern vaccine took off in the early 1800s, and the disease began to diminish in wealthier countries.
The Americas were the first to have a large scale eradication effort, and by 1950 there were only a few South American countries who still suffered from it. Most first world countries stopped vaccinating for it during the 1970s. (my mom -b.1971- was vaccinated but my dad -b.1972- was not). The vaccine uses a bipronged needle dipped in the solution to stab the arm a bunch of times, leaving a single pox scar.
The last naturally occurring case was in October of 1977 in Somalia. The last case ever was in September of 1978, after a lab contamination in the UK. After this, all stocks of smallpox were destroyed. Well, except two.
The only two known samples of smallpox are in the possession of the USA and Russia. This is a BSL-4 (highest biosecurity level) virus, and is contained at the CDC center in Georgia. The Russian sample is contained at VECTOR in Koltsovo. In 2014, more samples were found in Maryland, which were destroyed in Atlanta in 2015.
So now people are really concerned with it being used as a bioweapon, as we don't really vaccinate people for it anymore. We still have the vaccine and researchers and military are still sometimes vaccinated, but not on a large scale.
The entire genetic code of smallpox is available online for free. You might wonder if this is enough to make it. It is. In 2017, researches at the University of Alberta used the free genus info of horsepox (which was extinct) to bring it back to life. This shows that a pox virus can be recreated. They did this for about $100k.
So I guess the point here is that people could potentially weaponize this virus. We would be able to vaccinate against it, but as mentioned above, some forms of the virus near 100% fatality even in the unvaccinated. I mean don't worry about it, it probably won't happen. But, ya know. You probably didn't have enough anxiety, so here's some more.
Maybe next time I'll talk about weaponized anthrax.
I think a lot of people assume that when someone's DNA is run to match them to crime scene evidence, the entire sequence is read out and matched to the entire sequence of the sample. That's not true. What we're actually looking for are small areas of repeats.
So what is deoxyribose nucleic acid? It's made of a deoxyribose backbone with repeating bases, either adenine (A), cytosine (C), guanine (G) or thymine (T). Two strands are made and held together in a ladder-like fashion by the pairing of two bases. A binds to T and C binds to G. That's how it's stored, anyway. For DNA to be read and proteins made, we have to split it apart. That's also what we do when we perform polymerase chain reactions (PCR). That allows us to make millions of copies of DNA from a single sample. I won't go into the details here (i find that shit boring as hell tbh).
So when we have a DNA sample, we look at what's called short tandem repeats (STRs). These are highly polymorphic hypervariable areas within the genome. The repeats are usually 4-6 base pairs long and repeat between 4 to 40 times (typically).
STRs are found at certain places (loci) in the genome and are inheritable. You inherit and different number of repeats at each STR locus from your mom and dad. Therefore, two unrelated people are unlikely to have the same pair of sequences at an STR locus. Although people can have bands of repeats in common, it is overall a distinct pattern in each person. This unique pattern is your DNA fingerprint. Even looking at 5-10 loci, the odds that you and someone you aren't related to would have the same fingerprint is 1 in 10 billion.
Some people will say that isn't true (namely the people who wrote the wikipedia page that says that *a study claimed* that DNA fingerprinting is wrong, even though that isn't what the study says), but I know several geneticists (yk the people with PhDs in genetics) who have told me that there is almost no chance DNA evidence is wrong. The FBI uses it for a reason. It works.
You can fingerprint for paternity tests, or more interestingly, for crimes. Hair, blood, etc. it all has DNA, and it can all be sequenced like this. Now you know.
I want more chronic pain whump. Give me a cocky, independent character who suddenly can’t walk because a sudden rain storm aggravated their old leg wounds and now they have to lean on a friend to get home. Give me a usually stoic character shaking with pain during a flare up. Give me a character who’s finally healed having their first bad pain day and abruptly feeling like they’re back at square one.
Coughing up blood doesn't make sense for 99% of injuries and illnesses in fiction but it's HOT and I think the sexiness of whump outweighs the medical accuracy most of the time. I WILL die on this hill and I will be coughing up blood as I do so.
@goldenmoonangel pretty true. The only thing I see that I would consider stupid is "don't run before being stabbed." First, your sympathetic nervous system typically dominates during period of stress (such as when you are attacked), and therefore your heart rate will elevate. Secondly, with hypovolemic shock, heart rate increases to try and make up for the lack of volume and maintain cardiac output (CO still decreases, however). Your vascular will also constrict in order to increase blood pressure and maintain perfusion to vital organs (compensated shock), but it will ultimately fail if blood loss continues (decompensated shock). The values on this presentation roughly compare to the four stages of hemorrhagic shock, as well, so points there.
From Night of the Living Dead to Resident Evil, we all love good zombie horror (at least i do). But how do we make it realistic? Of course, zombies aren't real and this couldn't really happen, but we can take a look at a few real diseases and some other things to help a zombie story feel a little more grounded. We'll do it all in four easy steps. Bear with me, cause this is gonna be a long one.
Step 1: What caused the outbreak?
And I don't mean this as a vector or patient zero, necessarily, but that can add some depth to your world building. But first, we need to know if it's a virus, bacteria, or fungi (so no supernatural shit here). Real life fungi can infect certain bugs, incubate in them, and then cause them to do weird shit that eventually allows the fungi to reproduce (see cordyceps). I personally hate fungi and love viruses, so I would probably choose that, but you do you.
Step 2: How does it spread?
Personally, I like biting. I think that's fun. But I'm getting ahead of myself. So, with disease transmission, you have five general categories: direct contact (touching blood, pus, tissue, respiratory droplets, etc.), indirect contact (touching a doorknob a sick person touched, airborne, etc.), vector-borne (mosquitoes, flea, etc.), food borne, and water borne.
I think most zombie media uses direct contact (biting), but others have used airborne transmission (everyone gets infected even if they weren't close to a zombie). Vectors can also add a bit of pizzaz, since we can't really effectively stop bugs from biting us during an apocalypse. I guess you could use the fecal-oral route like dysentery, and personally I find that funny for some reason. The whole world turns to hell because someone shit in the drinking water (which is actually super realistic).
But back to biting...there's a fun virus (rabies) that causes increased aggression and salivation. This works in the virus' favor, as a dog who can't swallow (the virus makes this painful) and is salivating like crazy, will be able to effectively transmit the virus when it bites someone. Rabies also causes a lack of coordination and alters consciousness.
Just make sure whatever you choose for transmission makes logical sense for what the virus does. It makes people angry and bite? Well we oughta just spread it that way.
Step 3: Does it kill people? Does it reanimate the dead or are the zombies still "alive"?
This is sometimes skipped in some world building, and it leads to very confusing stakes. Going back to rabies for a second (i'm a big fan), we don't often see squirrels with rabies. This isn't because they aren't carriers for it, but because the bite that spreads it to them is often fatal (ofc they can still have it and there are more methods of spread than a coyote). So, you have to figure out, does the virus kill people who then become zombies, or does it just lie dormant until the person dies?
We're getting into the supernatural a bit here (it's horror okay), because people can't really reanimate after death (there was an interesting study recently with reanimating pig brains after 4 hours, but that's neither here nor there). So, if we decide that these are corpses that have been brought back to life, we have to decide if their wounds are what killed them or if the virus itself is deadly. In The Walking Dead, everyone who dies becomes a zombie, even if they die in their sleep. So everyone is infected, and the risk of zombies is that human bites are crazy dirty (especially with those dirty fuckin teeth on those things) and can cause infection. Or they just tear your throat out.
If you want to go the non-supernatural route and say that the people are still alive, then that's great. We love necrosis on a living human. We already talked about aggression, but I want to make a note here about dementia. Zombies would have some form of this, as they obviously can't remember what in the fuck they're doing if they just stand around in the street like that. Fun fact, some studies show that certain degenerative diseases are transmissible (like Alzheimer's -- look it up it's riveting stuff).
Now I want to talk about Creutzfeldt-Jakob's Disease. This is also called mad cow disease, and is a prion disease caused by eating infected beef. Kuru is a similar disease that results from eating infected humans. These are both caused by prions, misfolded proteins that cause other proteins to become misfolded. Both cause behavior changes, ataxia (trouble walking), jerky movements, hallucinations, psychosis, and dementia.
Step 4: Make it fuckin interesting.
So we got necrosis (either they're alive or dead, but they are ROTTING). We got aggression (amygdala, hypothalamus, and prefrontal cortex, mainly). We got hunger (the center for hunger and thirst is the hypothalamus, a wonderful target for your disease). We got all this shit being spread around.
But this is not the fun part of a zombie apocalypse. The fun part are the people who aren't infected. The survivors. Is the whole world fucked? Is there anywhere safe? This is the shit that makes a story good. People are also dangerous. Not infected people (zombies), but normal people in abnormal situations. People act aggressive when they want to live. They act irrational.
Back to medical stuff for a second. The world is dirty. Normal diseases are still present. People in an apocalypse are gonna be dropping left and right from things we don't even think about. A small cut, the bubonic plague, the flu, gum disease (no one ever carries toothpaste in the movies). They're also gonna have shit go wrong that doesn't kill them. Maybe they get glaucoma and go blind in one eye. Maybe they take a blood pressure med and they can't get it anymore. I mean, no one wants to read a fuckin SOAP note in the middle of a book, but I love this kind of shit, I think it makes the world feel more realistic. So add random crap going wrong. It ups the stakes and really differentiates their fucked up world from our own.
Closing Notes
I know this was kinda a ramble, but hopefully it made you think about some things. Worldbuilding things and such. I really enjoy writing horror stories and playing horror games, so I might do some more posts about stuff like this. Spooky season is also upon us, so I might do some more monster stuff. We'll see. Thanks for reading all the way to the end :))
A lot of people are farsighted (hyperopic) or nearsighted (myopic), though many more people are myopic (about 40-50% of US adults). Hyperopia is the inability to focus on objects that are near to you, and myopia is the inability to focus on objects that are far away.
First, we need to discuss what a lens is. A lens is a clear object which refracts and focuses light. This will take an image that is in front of the lens and make an image behind the lens (in this case, on your retina). An important concept is the lens equation (1/o + 1/i = 1/f). o is the object distance from the lens, i is the image distance from the lens, and f is the focal length. The focal length is the distance from the lens to the focal point, where the sharpest image is produces. You want this to be on the retina.
Your eye has little tiny muscles in it (called ciliary muscles) that contract to change the shape of the lens. This is done because you cannot change the distance to the object or image, only the focal length (which is related to the radius of the curvature of the lens). You do this subconsciously in order to create a crisp image of whatever you want to focus on (isn't that neat?!). The ciliary muscles contract (as part of the accommodation triad) when you want to read something up close, allowing the lens to return to its normal shape.
People with farsightedness (hyperopia) have eyes that are too short for their lens. This means that even when their ciliary muscles have contracted and their lens is allowed to return to its fullest shape, the image is still focused behind the retina.
People with nearsightedness (myopia) have an eyeball that is too long. This means that even when their lens is fully tensed and thinned by the fibers around it, the image is still focused in front of the retina.
So how do we fix this? Well, you can do it with glasses and contacts, which act as a second lens so that the light that hits your biological lens is then refracted to hit your retina. We can also fix this surgically with LASIK and PRK. LASIK is a surgery where a flap of your cornea is cut off and then the tissue beneath it is thinned out. Then the flap is put back. This may not be the best option for people who have a thinner cornea or need a higher degree of correction. PRK is simpler, in that your cornea isn't cut, just reshaped with a laser. It has a longer healing time but is a good option for people with a higher degree of correction needed.
I've seen a lot of dead bodies in my time. Usually, I think nothing of it in the moment because I'm working. But one thing always trips me up, whether it be a former patient or a cadaver, and that's nail polish. For some reason, when I see a body with painted nails, it makes me stop and actually see them as a human being. Because someone put those coats on. And I wonder if they knew it would be the last one. I wonder if they might've picked a different color if they knew it was the one they would die in.
