The average person has a lot to remember to do every day, so it's lucky for us that our bodies take care of many key actions such as breathing and digestion without us having to think about them. There are other involuntary actions, though, that don't seem to make sense and can even be downright annoying.
Business Insider took a look at six of the most mysterious involuntary actions and created images to explain why they occur:
Yawns have long been believed to be contagious because of empathy, as people with autism or other conditions that alter their social perception are less likely to "catch" yawning by seeing others do it. A 2014 study out of Duke University found that empathy alone can't explain it. According to the researchers, a better understanding of why yawns are contagious would likely lead to a deeper understanding of autism and schizophrenia.
Hiccups are spasms of the diaphragm, the muscle that plays a key role in breathing. Some diseases or conditions lead to chronic hiccuping, lasting days or weeks at a time. There is a medication that can treat some serious hiccup cases depending on the cause, but there isn't much evidence that random, short-term hiccups have a specific cure.
That's right: holding your breath, drinking water upside down, and having someone scare you aren't evidence-based treatments. But hey — it gives you something to do while you wait them out.
3. Pins and Needles
Paresthesia is the technical name for that awful prickly sensation that occurs after you go to move a limb has fallen asleep. While most cases of this sensation are temporary, some nerve disorders make this feeling a chronic annoyance.
4. Hypnic Jerks
If you've ever been on the verge of falling asleep and then suddenly startled awake because you jumped or twitched in your sleep, you've experienced a hypnic jerk. The body paralyzes itself during sleep to keep us from acting out our dreams, and hypnic jerks are a mild failure of that mechanism. Some scientists believe that it could have been an evolutionary advantage to avoid becoming too vulnerable to predators during sleep.
5. Eye Twitches
Spasms in an eyelid cause myokymia, more commonly known as eye twitching. Because it is caused by a number of lifestyle factors, the best way to prevent this is by well-rounded, healthy living. While it can be fairly irritating, it usually isn't a symptom of a larger, serious problem and will pass on its own.
6. Photic Sneezing
About a quarter of the population has a photic sneeze reflex, meaning they sneeze when they see bright lights. While it might seem annoying to sneeze because of lights, it's better to go ahead and sneeze into a tissue or the crook of your elbow instead of holding it in. Sneezing generates a tremendous amount of pressure and it can be damaging if you don't release it.
Learn more about these phenomena at Business Insider.
Cover image: Shutterstock