This actually made me schedule my annual checkup.
A few weeks ago, Reddit user Immediate_Hair_3393 turned to the popular Ask Reddit page and asked doctors, "What do we not know about the human body?"
Studio4 / Getty Images
A ton of doctors (and other healthcare professionals) of various specialties replied, and their answers ranged from interesting to weird to a little bit horrifying. So, I decided to share them with you! Here are some of the best:
1. "We apparently don't know precisely how our bodies can distinguish gas from poop. We have some ideas, we know there are a ton of nerve endings in the area, but the precise mechanism of our bodies telling our brains, 'This is a fart, let loose' isn't really understood."
Universal
"What blows my mind is, it's distinct enough that we even pass gas while asleep. That difference must be wired DEEP!"
—u/BIGJFRIEDLI
2. "One of the few ABSOLUTES in medical science is that nobody born blind has ever developed schizophrenia."
—u/beboleche
3. "I’m a dermatologist. We don’t know what exactly causes itching, like the molecular pathways for it. That’s why it can be so hard to find a good treatment when a patient comes in for itchy skin."
Kinga Krzeminska / Getty Images
—u/criduchat1-
4. "I’m an anesthesiologist. We still don’t really know why inhaled volatile anesthetics like sevoflurane, the principle anesthetic agent used to maintain general anesthesia, work."
Skaman306 / Getty Images
"We kind of have an idea of maybe how it happens, but really we don’t know. It’s commonly said in my field that whoever figures this out will win the next Nobel Prize in medicine."
5. "I tell my residents that only about 40% of what we do is evidence-based. Much of what we do is based on flimsy evidence, or grossly inadequate follow-up."
LaylaBird / Getty Images
"For instance, the longest semaglutide trials are around two years (they make it sound longer by reporting the duration in weeks, 104, for SUSTAIN-6 and STEP 5). What's the plan for following up to see if these drugs are safe for five, 10, or more years?
There is an encouraging trend toward reviewing 'established' treatments, with a bunch being subject to 'medical reversals' (see the book of the same name). Think of 3V coronary disease and estrogens in menopause as the prime examples.
This is a roundabout way of saying we mostly don't even know what we think we know about the body.
If you want to lose sleep about how fragile we are, consider the basilar artery. This single point of failure to your brain stem is only about three millimeters wide, with flows of about 150 ml/minute. Three millimeters is a bit over 1/10 of an inch.
Also, we have no idea why we sometimes shiver when finishing peeing."
6. "I'm a sleep specialist. While we do have some good theories about some of the functions of REM as far as how it affects the brain and health, we still don't fully understand the purpose of dreaming."
Jacob Wackerhausen / Getty Images
—u/3Magic_Beans
7. "OBGYN here: We still don’t know exactly what makes labor start. We know all about the mechanics and physiology, but we don’t know what makes the average uterus say it’s 'go time.'"
Halfpoint Images / Getty Images
—u/_mcr
8. "We don’t fully understand the omentum’s function. For years it was thought to be just connective tissue in the gut, but now we’ve learned it's a whole organ affecting the gut-brain axis that we have very little understanding of."
Benote / Getty Images
—u/Angiebio
9. "The gut microbiome. While it's well-known that the gut plays a huge role in digestion, researchers are discovering just how much our gut bacteria affect other parts of our health, like mood, immunity, and even brain function."
Koto_feja / Getty Images
10. "I have a very niche answer: we don’t know what is supposed to naturally bind to the area in which benzodiazepines work."
Cappi Thompson / Getty Images
"Benzodiazepines, BZD, are medications like Xanax and Valium. They produce anti-anxiety effects, and they have a very distinct chemical shape to fit into the BZD site in a group of five proteins.
But we don’t know what is supposed to go there. Many medications are analogs of naturally binding molecules that we copy and then use to create an effect. The BZD site is for something, we just don’t know what."
—u/Mrzahn
11. "Apparently we know next to nothing about fibroids, which like 75% of women have at some point in their lives. That's great, considering that the largest one ever removed was 100 pounds, so not exactly a minor issue."
Paul Biris / Getty Images
"There are theories about different hormones and what things put you at higher risk, but aside from having surgery to have your existing ones removed, there is basically no information on what you can to do prevent them from coming back."
12. "There are smell receptors in the nose for things that don't exist. They're called 'orphan olfactory receptors.'"
Pop TV / CBC Television / Via giphy.com
13. "The placenta is the only human organ grown for a specific purpose and discarded when it is no longer needed."
14. "Not a doctor but a speech pathologist. We still don’t fully understand what causes people to develop a stutter. We know there’s sometimes a genetic link and that some children do it as a developmental stage that they grow out of. It’s very difficult to treat."
NBC / Via giphy.com
15. "We don't know what kind of ramifications menopause really has on the female body."
Fiordaliso / Getty Images
"We also don't know how the female body actually reacts to many kinds of medication in contrast to the male body, since for too long the 'standard' has been male test subjects."
—u/FedUp0000
16. "We don't know what causes endometriosis or how to treat it effectively. The leading theory is 'retrograde menstruation,' which occurs in 80-90% of women. OK…so why do 80-90% of women not have endometriosis?"
Paul Biris / Getty Images, NBC / Via giphy.com
"The only way to remove or get rid of endometriosis is through surgery, but there is a high rate of recurrence after surgery. Some women undergo multiple surgeries for it."
—u/looooongsigh
17. "We don’t understand the pathophysiology of preeclampsia or what causes the onset of labor."
—u/bpm12891
18. "I’m a PA, retired after 40+ years of clinical practice and academic work. I can tell you that the more we learn, the more we realize there is left to learn. The placebo effect is real. We don’t know exactly how, but it does work; and not just with pain relief."
Ion-Bogdan Dumitrescu / Getty Images
"Many drugs we use routinely work great, but we don’t exactly know how they work. The pharmacology is unclear. Although newer technology has given us greater insight into how the brain works, there are still a lot of unknowns.
Every time I’ve wanted to learn more about a specific subject, I end up with more questions than answers. It’s why I love medicine."
19. "There are a lot of theories but no concrete answers on why identical twins split."
Dave Nagel / Getty Images
"Identical twins are also at way higher risk of defects and specific issues throughout pregnancy, so a better understanding of the mechanics would be beneficial."
—u/oat-beatle
20. And finally: "We don't know why people get certain kinds of cancer. My aunt had lung cancer (which was thankfully caught and treated early) even though she never smoked, and no one knew exactly why."
Peter Dazeley / Getty Images
—u/Kevin-W
So, what do you think? If you're a medical professional or a patient, I'd love to hear your thoughts. Leave your comments down below!
Or, if you have something to say but prefer to stay anonymous, feel free to check out this anonymousGoogle form. Who knows — your answer may end up in a future BuzzFeed article!
21.
Note: Responses have been edited for length/clarity.
