02/12/2012 10:58 am ET

Valentine's Day: How Love Changes Your Body Chemistry

By Danny Deza

Ah, love. In the heady days of a mutual crush, pulses race, knees go weak and heads reel. So strong are these feelings, they've launched a thousand songs and poems.

But it's more than just a metaphor. Love does indeed impact our bodies in measurable ways.

You feel different and are different. Read on to find out what researchers have discovered about this thing called love.

love chemistry