What is a Kidney Function Test?

Kidney function tests are done to assess how well your kidneys are working. They may also help your doctor diagnose kidney disease early and stop it before it worsens.

These tests include blood and urine tests, as well as medical imaging. Your doctor may order them if you have risk factors for kidney disease such as high blood pressure, diabetes, a family history of kidney disease, or other health conditions.


Urinalysis is a series of tests for kidney health that use urine to monitor your health. It is often used to check for urinary tract infections, kidney problems, or diabetes and can be part of a regular medical checkup or when you are about to have surgery or are pregnant.

A urinalysis is usually done by a doctor or nurse and involves a visual exam, a dipstick test, and a microscopic exam of your urine. The results of the urinalysis will help your doctor make a diagnosis and plan treatment for your condition.

Your urine will be examined for signs of blood, bacteria, yeast, crystals, and casts. These can be signs of urinary tract infections, kidney problems, bladder stones, kidney cancer, or other conditions.

You may also see leukocytes (white blood cells), erythrocytes (red blood cells), or bilirubin, a waste product from the breakdown of old red blood cells. Normally, these substances are removed from your body by the liver.

Blood in your urine is okay, but further testing is required to find the cause. It is a sign that you may have an infection or a kidney problem, so it’s important to get tested immediately.

It’s also important to note that the urine sample will change from when it is collected to when it is analyzed in the laboratory. This is because many things can affect the concentration and pH of the urine, including your diet, exercise, chemical imbalances, and other health conditions.

Blood Tests

Blood tests help doctors diagnose, treat or monitor certain diseases and conditions. They also show how well medications are working and assess organ function.

Most blood tests can be done at home, but some require a visit to a lab. These tests can provide a more detailed picture of your health than a doctor’s assessment, and some can better indicate how quickly your condition is progressing.

For many blood tests, a phlebotomist will draw a small amount of your blood from a vein. The phlebotomist may use a needle that feels like a small prick, but it is usually very painless and only takes a few minutes.

A complete blood count, or CBC, is one of the most common blood tests that a healthcare provider might do to check for various diseases and conditions. This test measures different components in your blood, including white and red blood cells.

This test measures the total volume of red blood cells in your blood. A high or low blood count can indicate various diseases and disorders, such as anemia, hepatitis, or arthritis.

These blood cells carry oxygen from your lungs to your body’s tissues. A low blood count can signal a deficiency in the oxygen your body needs to function, indicating certain cancers or infections.

If your CBC shows low levels of red blood cells, a healthcare provider might suggest an iron test to ensure you are getting enough of this mineral. Alternatively, your doctor might recommend other blood tests, such as a ferritin test or an ammonia test, to check the level of these waste products in your body.


Kidney function tests are used to diagnose kidney diseases and to see if you have problems with your ureters (small muscular tubes that join the kidneys with the bladder). Ultrasound, or sonography, is an imaging test that uses high-frequency sound waves to produce pictures of the inside of the body.

A kidney ultrasound is safe and doesn’t use radiation like an X-ray. In addition, it’s painless. It’s usually done on an outpatient basis without the need to fast, and most people do not experience any side effects from the procedure.

CT Scan

A CT scan is an x-ray test that uses very detailed pictures to help diagnose and treat health problems. They also check how well your kidneys work and if you have kidney cancer.

They can detect cancers that have spread from the kidneys to other body parts, such as the lungs or heart. They can also help doctors plan surgery if there is a problem with the kidneys or their blood vessels.

Before your CT scan, you will be injected with a contrast agent that makes certain body parts stand out better on the x-ray picture. This contrast can damage your kidneys if you have chronic kidney disease (CKD), so you will need a blood test to ensure your kidney function is normal before getting the CT scan.

You may be asked to drink extra water before your test and after it finishes. Hydrating your kidneys are important because they help remove the contrast from your body after you get a CT scan.

The risk of kidney disease from the CT contrast is very low. It is usually only 1% of the time, even in people with CKD or a low glomerular filtration rate (eGFR).

If you have a history of kidney problems, let your doctor know about them before getting a CT scan. They can give you other tests to help diagnose your problem before they prescribe a CT scan.