Ammonia is a highly toxic substance that can cause severe health problems, including death. It is produced by the breakdown of proteins in the body and is excreted by the kidneys. If the kidneys are not functioning properly, ammonia can build up in the blood and cause a condition called hyperammonemia. This can lead to confusion, seizures, coma, and death.

Uric acid is also a waste product of protein metabolism. It is less toxic than ammonia and is excreted by the kidneys. However, high levels of uric acid in the blood can cause a condition called gout, which is characterized by painful inflammation of the joints.