How can a doctor check if a persons kidneys are working well?

A doctor can assess kidney function through several tests. Blood tests to measure serum creatinine and blood urea nitrogen (BUN) levels provide insight into kidney performance, while the estimated glomerular filtration rate (eGFR) helps evaluate how well the kidneys filter waste. Urine tests can also be conducted to check for protein, blood, or other abnormalities that may indicate kidney issues. Additionally, imaging studies like ultrasounds may be used to examine kidney structure and size.