7 Weird Facts About the Human Body

February 7, 2023 • Shannon Flynn


What would happen if you could never burp? How long can your hair physically grow, and what’s living in your eyelashes right now? Sometimes, truth is stranger than fiction. Here are seven weird facts about the human body that will make you think differently about our species. 

1. The Longest Recorded Pregnancy Lasted Over a Year

Think carrying a baby for nine months is exhausting? Try being pregnant for 375 straight days! In 1945, Beulah Hunter gave birth to a daughter after just over 12 months of gestation. 

No one is sure why her pregnancy lasted so long — everything seemed to proceed normally until around three months, when baby Penny Diana apparently stopped growing. Thankfully, she resumed normal development and began to move somewhere around the six-month mark. Despite her long stint in her mother’s womb, she was born just six pounds, 15 ounces.

2. Some People’s Organs Are Reversed

Another weird fact about the human body? Your organs can be in unexpected places. 

Situs inversus is a rare condition in which your internal organs are on the wrong side of your body. If you have situs inversus, your heart and stomach are on the right side, your liver is on the left and so on. 

Although cardiac issues can be more common than usual with situs inversus, having your organs on the opposite side is usually harmless. In fact, most people don’t know they have the condition until they get some kind of medical imaging done. 

3. Your Hair Has a Growth Limit

Because most people get regular haircuts, many people don’t realize the hair on your head can’t keep growing indefinitely. 

The maximum length your hair can achieve depends on your body’s predetermined anagen phase. That’s the cellular phase in which your hair follicle is alive and actively growing. 

The length of your hair’s anagen phase is probably genetic. For some people, it may last only two years, meaning your hair will stop growing at the two-year mark. For others, it lasts as long as six years, giving you just over half a decade to grow your luscious locks before they reach full size. The world’s longest recorded hair was 18 feet, five inches long, as the Guinness Book of World Records confirmed in 2004. 

And, in case you were wondering, the anagen phase for body hair is just a few weeks. Thank goodness! Imagine if your armpit hair or eyelashes grew as long as the hair on your head. Speaking of which…

4. You Probably Have Eyelash Mites

Just along the edges and folds of your eyelids live Demodex mites, which are microscopic arachnids — arthropods related to spiders — that love to eat dead skin. 

Don’t freak out! As creepy as it may seem, Demodex mites are a normal part of your body’s microbiome. The average person has 10 times as many microbes, like mites and bacteria, as they do human cells in their body. Demodex mites actually clean up excess oil and dead skin that might otherwise build up around your eyes. As long as you don’t get a blocked oil gland that allows them to reproduce more than usual, they won’t cause a problem. 

5. Some People Physically Can’t Burp

If you’ve never let out so much as a tiny belch, you might have retrograde cricopharyngeus dysfunction (RCPD). 

Although it sounds like a nice problem to have — we’ve all experienced the awkwardness of burping at an inopportune moment — the disorder can actually be debilitating. Due to the esophagus not opening properly to let out air, RCPD sufferers often experience extreme abdominal pain, bloating, gagging and excess gas. A bizarre croaking sound in the throat is also common. 

For most people, the treatment is a shot of Botox in the afflicted part of the esophagus to help the muscle relax. Often, a single round of this paralyzing agent treats the disorder for life. Sweet relief! 

6. Men Apparently Can’t Do the Chair Challenge

In 2019, a social media dare called the Chair Challenge went viral. Here’s how it works:

  1. Stand with your toes touching a wall and put your feet together. 
  2. Take one step back with your right foot, placing your right toes right against the heel of your left foot. 
  3. Now, step back with your left foot so both feet are side by side. 
  4. Keeping your legs straight, bend at the waist until the top of your head is against the wall. 
  5. Next, have someone slide a chair under your chest. 
  6. Finally, while keeping your head on the wall, lift the chair off the ground and try to stand up. 

Women can usually lift the chair and stand up straight with ease. Men, on the other hand, are almost always unable to do this seemingly simple task. Why?

Men and women tend to have a different center of mass. A woman’s center of gravity sits 8-15%  lower on the body than a man’s. As men move their feet away from the wall, they extend their center of mass into a position where their muscles can no longer act as a lever and allow them to stand up. Make a bet with your male friends and challenge them to try it!

7. You Get a New Skeleton Every Decade

Your body is constantly under renovation. Although most people build the bulk of their bone density by age 30 — and start to lose density from that point on — that doesn’t mean your skeleton stops repairing itself.

Over the course of 10-year cycles, most of your skeleton is completely replaced with new bone. So, if you’re turning 40, you can happily announce that you’re starting on your fourth skeleton! 

It’s Fun to Learn Weird Facts About the Human Body

Although we all share the experience of being human, there’s still a lot of variation when it comes to our physical selves, and there’s still a lot we don’t know. One thing’s for certain — the human body can be truly amazing. Which of these weird facts about the human body surprised you the most?