Here's an idea you may not expect: Love is as basic as our needs for food and water.
When we're craving things like food, water, or drugs, or anticipating getting them, two areas deep within the brain, the ventral tegmental area and caudate nucleus, are active. A neurochemical called dopamine is released from the ventral tegmental area into the caudate nucleus. Neuroscientists have produced brain scan images of the brains of people falling in love, when they're feeling the passion of a very new relationship that has yet to become comfortable and secure.
What they found is that the brain in love looks a lot like the brain craving or anticipating things like food or drugs. The same areas of the brain are active. Interestingly, this region is located in a different area of the brain from the region associated with determining physical attractiveness.
In other words, our brain makes a distinction between simply finding someone attractive and being mad about them, as they say? These emotions activate completely different parts of the brain suggests that romantic love doesn't just feel different than sexual attraction, but that our brains register these as two different urges.