People in love have unusually low serotonin levels, similar to those in people with Obsessive Compulsive disorder (OCD).
We all think that our heart loves someone and for us all feelings are related to our heart but that’s not true. Actually love is generated from our brain.
Falling in love isn’t as abstract a concept as you might think. Romance corresponds to a specific mix of chemicals in your brain and body, among them dopamine, adrenaline, and norepinephrine. Love also seems to lower serotonin levels, a symptom that’s common in people with OCD, and which may explain why the early stages of love are so obsessive. This chemical cocktail gives way to another one as a relationship moves from its initial, lovestruck phase into one of deeper understanding. At this point, the hormones oxytocin and vasopressin take over, prompting feelings of safety and affection.
Source: curiosity, sciencedaily