Why do we feel emotions in our stomachs?

There's a secret connection between your mind and your gut. Well, there's actually over 100 million secret connections ... but who's counting?

You've probably heard sayings like: you've got "butterflies in your stomach," "a knot in your stomach," or that what happened somewhere was "gut wrenching."

We even use phrases like "my feelings were hurt" -- which is meant to be a metaphor, but may have a more literal origin. We've known for a long time that sometimes we feel our emotions physically in the body. There are loads of MRI scans to back it up -- but why are so many of the negative emotions (like fear, anxiety, and disgust) felt in your stomach?

Dr. Anthony Komaroff of Harvard Medical Schools explains that the answer is pretty simple: your brain and your gut are best buds. They're in constant communication with each other, sending signals back and forth when your brain OR your stomach is distressed. Specifically, they're connected through the Enteric Nervous System, or the ENS, which has over 100 million nerves running directly from your brain ... to your stomach. So emotional distress can cause a distressed gut AND, strangely enough, a distressed gut can also cause emotional distress. It's a two way street.

What you'll notice about a lot of the emotions that people feel in their stomach ( butterflies, the gutwrench, the knot) is that they're all different ways of experiencing the same emotion: stress.

When there's something that stresses you out, it triggers the fight-or-flight response in the brain. This is an instinctive physiological response experienced by ALL animals in the animal kingdom. It's there to protect you in dangerous situations, to prepare you to fight in the case of an attack, or to outrun the predator. Part of fight-or-flight's physiological response is inhibiting the secretion of stomach juices while diverting blood flow from the stomach and into your lungs and muscles instead.

Pair this with all the stress hormones that your body is releasing, like adrenaline, and it produces a physical reaction that's experienced all over your body -- including your heart and your gut. Because of your brain's connection to the stomach through the Enteric Nervous System and the stomach's involvement in digestion, stress is also a common irritant of the digestive system. It can cause stomach aches, gas, constipation, diarrhea and a whole host of other wonderful conditions.

Some evolutionary scientists say that the human mind hasn't yet evolved to handle our not-actually-threatening 21st century woes. That's why a stress reaction meant to protect you from being eaten alive also happens all the time in everyday situations.