Being sad or in love can make you experience a lot of physical things. Have you ever felt your heart skip a beat? Felt the pain of a heartache? Butterflies in your stomach? There's a reason for that, and science has the answer.

It turns out, all those feelings are because of how neurons are firing in your brain. It can make us feel things very intensely.

According to Robert Emery and Jim Coan from the University of Virginia, feeling a heartache may be the work of the anterior cingulate cortex. This is where the brain regulates emotional reactions.

The anterior cingulate cortex becomes more active during stressful situations, and it stimulates the vagus nerve, which starts in the brain but is connected to the chest and abdomen.

There's even research to show what different emotions will make you feel in different parts of the body:

So, the next time you feel something like the above? Know that it's all just chemical.