Diagnosis of Kidney Failure

Chronic kidney failure is diagnosed based on tests and procedures. Many cases of change in kidney function or kidney disease are discovered accidentally during a routine blood or urine test. If any abnormality of kidney function is detected in the tests, the kidney function will be monitored with regular blood tests and treatment will be started at the earliest stage.

Blood tests: This test measures the level of waste products such as creatinine and urea in your blood, which are removed by the kidney. Another test that is done to diagnose kidney disease is assessment of glomerular filtration rate (GFR). This is the rate at which blood is filtered through the kidneys and can be calculated using parameters such as creatinine level, age, race and gender. Glomerular filtration rate decreases in chronic kidney disease or kidney failure.

Urine tests: Urine tests done to detect kidney failure include measurement of protein, presence of abnormal cells or measurement of concentration of electrolytes in urine. Protein is not normally present in the urine and is a clue that damage to the kidneys has occurred. Presence of casts (abnormal aggregations of red and white blood cells) in the urine is also indicative of kidney disease. Concentration of electrolytes in urine as compared with blood can help to determine whether your kidneys are functioning normally and are able filter blood or not.

Imaging tests: If kidney disease is suspected, the doctor may recommend imaging tests such as  ultrasound, MRI scan or CT scan to assess your kidneys' structure and size and find out whether there are any unusual blockages in your urine flow.

• Ultrasound: This is a painless and non-invasive test, which uses high-frequency sound waves that cannot be heard by human ears to obtain information about structures inside the body. The pattern of the echoes produced when the sound waves are reflected from the internal structure creates a picture called a sonogram. The radiologist can differentiate normal and abnormal kidney and other problems on this picture. It can show presence of stones, scars in kidney and many other abnormalities. In people with advanced kidney disease, the kidneys are shrunken and may have uneven shape.
• MRI scan or CT scan: These are also painless and non-invasive tests, but they can show details that may not be seen on an ultrasound. Both the scans provide good visual detail of the part of the body that is being examined. It can show smaller lesions and other pathologies in the kidney as compared with ultrasound. During a CT scan, a series of detailed pictures of the part of the body that is being examined is taken. A computer then combines these pictures to form images of the part of the body that is being studied. The radiologist can diagnose abnormalities on the basis of the images.

Kidney biopsy: In this test, a sample of kidney tissue is taken for testing. It is usually done with local anaesthesia with the help of a long, thin needle that's inserted through your skin and into your kidney. The tissue sample is examined under the microscope in a lab to determine the cause of your kidney problems.