Ammonia

Ammonia is a chemical compound made up of one atom of nitrogen and three of hydrogen (NH3). At normal temperatures and pressures, it is a gas. It is colorless, but has a strong, distinctive odor. It has several industrial uses as a disinfecting cleaning compound (mixed with water in solution), as a precursor chemical to the creation of chemical fertilizer, and even in the production of pharmaceuticals. However, it is caustic and toxic, even in moderate doses. However, in its liquid form, it is stable and easily handled. 
Animals, including human, create ammonia during the process of digesting protein. However, the ammonia created in this manner is transformed by the liver into urea, which is far less toxic and is disposed of in the urine. However, in patients with severe liver dysfunction (often typical of cirrhosis), ammonia can build up in the blood to the point where it can be detected on the breath. However, this buildup can also occur if the enzymes responsible for the process are missing, such as in disorders like ornithine transcarbamylase deficiency. Large quantities of ammonia in the blood can also result in confusion and even coma.
Ammonia at WikipediaCategory:Blood Chemistry