It is called urea
It means that you are producing nitrogen-containing waste in the form of urea.
Urea serves an important role in the metabolism of nitrogen-containing compounds by animals and is the main nitrogen-containing substance in the urine of mammals.
Many processes in the body produce nitrogen-containing wasted-products. This nitrogen will sometimes form ammonia, which is poisonous to the body.In order to remove this poisonous ammonia from the body, ammonia is converted to urea which is non-toxic for the body, and more easily removed. This happens in the urea cycle.Thus urea is a way of disposing leftover waste-nitrogen from our nitrogen metabolism.
Blood urea nitrogen test (BUN). Urea is a by-product of protein metabolism. This waste product is formed in the liver, then filtered from the blood and excreted in the urine by the kidneys. The BUN test measures the amount of nitrogen.
The most common metabolic mammalian waste product is urea. It is a colorless crystalline compound that contains nitrogen, and is excreted in urine.
The BUN test measures the amount of nitrogen in your blood that comes from the waste product urea. A BUN (blood urea nitrogen) test is done to see how well your kidneys are working.
Your liver converts the nitrogenous waste into urea, which is then transported out of the body when you urinate.