Urea (BUN)

Urea, often reported as BUN, is a waste product formed when the body breaks down protein and is removed by the kidneys. This blood test measures how much urea is present in your bloodstream.

A raised urea level may indicate that the kidneys are not clearing waste as efficiently as they should, though it can also be affected by hydration and diet. For this reason, urea is usually interpreted alongside creatinine to give a clearer view of kidney function.