# Why does urine smell like ammonia?

Apparently, water or $$\ce{H2O}$$ combines in some way with nitrogen (from the air or elsewhere?) to form ammonia, or $$\ce{NH3}$$. Where/how in the body is this $$\ce{NH3}$$ (or whatever nitrate) produced before it is excreted with urine?

• When excess proteins in the body are broken down, urea is formed (nitrogen containing compound). This is excreted in urine and in sweat. – surelyourejoking Sep 13 '14 at 6:50