<Tr> <Td> Urea </Td> <Td> At high concentrations (> 300 mg / dL (> 50 mmol / L)): headaches, vomiting, fatigue, carbamylation of proteins </Td> <Td> </Td> </Tr> <Tr> <Td> Creatinine </Td> <Td> Possibly affects glucose tolerance and erythrocyte survival </Td> <Td> </Td> </Tr> <Tr> <Td> Cyanate </Td> <Td> Drowsiness and hyperglycemia, carbamylation of proteins and altered protein function due to being a breakdown product of urea </Td> <Td> </Td> </Tr> <Tr> <Td> Polyols (e.g., myoinositol) </Td> <Td> Peripheral neuropathy </Td> <Td> </Td> </Tr>

What causes high levels of urea in blood