The human body is a wild and complicated machine. There are all sorts of strange facts about the body that you’ve probably never heard before. We’ve chosen 60 of the most interesting ones to share with you today. Some of them will literally blow your mind. For example, we’ll teach you about Exploding Head Syndrome. Yes, it’s real!
Other facts are just as fascinating. From the help blowing on your thumb gives to learning about how far your heart can squirt blood across a room, this list has it all. You might be surprised by just how much you don’t know about yourself.
1. Human teeth are as strong as shark teeth.
Although the teeth of sharks are made from a harder mineral than human teeth, they are still similar in strength. It is largely due to the enamel coating on them. The enamel is comparable in each species.
2. When people blush, so does their stomach lining.
Both the human stomach and the face become red when blushing. It’s because it causes all of your capillaries in your body widen. The increased blood flow is responsible for the red color.
3. The brain generates enough electricity to power a light bulb.
There is a lot going on up there. The brain is constantly sending electrical signals and impulses between the billions of neurons. Combine them all together and you can power a low-watt bulb.
4. Having your heart broken actually causes a heart condition.
It is called broken heart syndrome and it’s entirely real. The emotional stress can cause chest pain and shortness of breath similar to a heart attack. It normally resolves within a few days or weeks.
5. Humans can make up to 7,000 different facial expressions.
We have many more facial muscles than our primate ancestors. Also, part of having no hair on the face means that our expressions are easier to see too. There are thousands of different possibilities.
6. Some people hear the sound of a bomb going off when falling asleep.
The name for this weird experience is exploding head syndrome. It sounds like a loud gunshot or explosion and happens upon sleeping or awakening. It has been estimated that it affects up to 10% of the population.
7. Human hair is pretty much indestructible.
One of the only real threats to hair is fire. Besides that, it decays at an extremely slow rate. It’s even resistant to various types of chemicals and acids.
8. There is a syndrome where people become obsessed with fine dining.
It’s called Gourmand Syndrome. It happens due to an injury of the right anterior cerebral hemisphere of the brain. Afterward, the individual will show a preference for eating and thinking about fine foods.
9. Stomach acid is strong enough to burn a hole in your skin.
Individual stomachs vary in levels of acidity. However, the hydrochloric acid produced by your body is not only strong enough to break down food but in many cases, it can even bore through a piece of wood.
10. You can reduce stress by putting your thumb up to your mouth and blowing
It sounds strange, but blowing on your thumb is a great stress reliever. It works by cooling off the thumb and calming the pulse in it. This, in turn, causes your body to feel more relaxed in general.
11. There is likely more bacteria in your mouth than people living on Earth.
The bacteria love the warm and moist environment. It thrives in there. There are at least 615 documented types of bacteria you might find, and their levels in your mouth can number in the billions.
12. Babies have more bones in their bodies than adults do.
Humans are born with at least 300 or more bones. However, many of these fuse together slowly over time. Adults ultimately end up with a total of 212 different bones.
13. If laid side by side, the length of your blood vessels would circle the world more than twice.
Between the arteries, veins, and capillaries, there are a lot of blood vessels in the body. They are winding all throughout every inch of your limbs. Line them up and they would likely stretch between 60 to 100 thousand miles.
14. The human eye can see at a resolution of 500 megapixels.
This estimate includes your whole field of vision spanning 180 degrees. It would take a very high definition camera to match this. The eye is superior to most devices.
15. There is ten times as much bacteria in the body as there are human cells.
Bacteria is much more plentiful than actual cells. The giant microbial communities have a serious effect on health. Yet, they are still largely unstudied by scientists.
16. Your skin makes up around 16% of your body weight.
In the average adult, that means around 20 pounds or more of just skin. If you peeled it off and lined it up, it would cover an area of about 22 square feet. Now that is a lot of skin!
17. There are mites living on your eyelashes.
They inhibit other hair follicles too. It’s a little weird to think about. The species of mites is known as Demodex, and it’s possible that they are what is behind various skin disorders.
18. Every ten years, the human skeleton regenerates itself.
The bones are regenerating around the clock. At any one time, there is a large mix of old and new bones in the body. The process never stops, but as we age, it does slow down.
19. The heart can squirt blood up to thirty feet in distance.
It is a living pump with a lot of pressure that can send blood flying all the way across a room. It is very strong. The heart pumps around 2000 gallons of blood every day.
20. Our eyes are closed 10% of the time that we are awake.
This is mostly made up of the time spent blinking. A blink only lasts a split second, but we do it a lot. The average person blinks around 15 to 20 times per minute.
21. The heart can continue beating once taken out of the body.
That is how they do heart transplants. The doctors keep the heart beating while they transport it to the receiving patient. The procedure is completed about 5,000 times every year worldwide.
22. All of your blood gets filtered by your kidney 25 times per day.
It comes out to around 180 liters of blood processed daily. The average body contains seven or eight liters in total. The kidney filtration is crucial to keeping your blood healthy.
23. There is a type of tumor that grows on teeth and hair.
We normally think about tumors growing on the skin or organs. However, there is a type of cyst called teratoma that involve tissues like bone, hair, and teeth. They can be removed by surgery.
24. The pink corner in your eyes is related to bird and reptile species.
It is an evolutionary remnant from the past. It used to be an inner eyelid similar to those that birds and reptiles have. After millions of years of evolution, there is not much left.
25. You are shorter at night when you go to bed.
Your height is the tallest first thing in the morning when you wake up. Over the course of the day, your spine gets compressed. There is a gelatin-like material in between your discs that acts as a cushion. It moves around while you sleep.
26. The liver can regenerate to its full size even if 75% is removed.
Take away three quarters of the liver and it can still survive. It will slowly grow back over time. It is the only organ in the body that has the capacity to regenerate.
27. Every ten years after age 30, you lose about a half an inch in height.
As people grow older, they also get shorter. It’s because the discs between the vertebrae start to flatten. It happens very slowly and most won’t even notice the change in height.
28. The human heartbeat can synchronize with music.
Depending on the beat and tempo of the music you are listening to, your heart beat will speed up or slow down. Songs that have crescendos in them can cause blood vessels in the cardiovascular system to constrict.
29. You lose around half of your taste buds by age 60.
Humans begin with about 10,000 taste buds. However, due to age, the way things taste changes over time. Taste buds really only last around ten days before changing.
30. The enzymes that digest food also digest your body after you die.
After death, the enzymes begin working on you. The microbial organisms can feed on the fluids produced during autolysis — the process that occurs once you pass away.
31. Kissing can help prevent cavities.
When you kiss, your mouth produces more saliva. Getting your fluids secreting like this helps to wash away plaque. Less plaque means fewer cavities.
32. Humans are made of stardust dating back billions of years.
People have about 97% of the same atoms as the galaxy that we live in. As a result of supernovas, stars explode and the dust forms into new planets, and ultimately, people. Around 93% of the mass of the body is actually stardust.
33. Humans glow in the dark.
Our bodies are bioluminescent, meaning in the dark, we give off light. It’s just too faint to be seen by the human eye. Species like fireflies and some jellyfish exhibit this property much more strongly.
34. In a lifetime, the heart pumps about 200 million liters of blood.
The heart contracts over 100,000 times every day. It is always pumping away. With exercise, it pumps up to six times as fast as normal too.
35. In the 1940’s, most people dreamed in black and white.
About three-quarters of Americans reported that they almost never saw color in their dreams back then. It is believed to be because of the exposure to black and white television and films. The percentage of people that report this phenomenon now is much smaller.
36. The mouth produces one to two liters of spit every day.
It’s enough to fill two to four water bottles. Your salivary glands can be triggered just by thinking about food. When you are eating, they work even harder.
37. When you are submerged in water, your body triggers a “diving reflex”.
It causes certain systems in the body to shut down and conserve energy. There are actual physiological changes. It is clear from the research that humans have a long aquatic history.
38. If you untwisted all of your DNA, it would be long enough to traverse the solar system twice.
DNA is made up of long coils. If unwound, your DNA would stretch all the way from Earth to Pluto and back again. In every single cell, there is about 2 meters worth of DNA.
39. Tears have a different composition depending on whether they were shed for sadness or happiness.
The emotion that causes the tears to form matters. There are a total of three different types of tears. Each of them looks different when examined under a microscope.