How to Test for Kidney Disease

Kidney disease is a prevalent condition affecting millions in the United States and can sometimes exist without a person even knowing. Detecting this disease early on can make a huge difference in facilitating early treatment and helping preserve the kidneys’ health as much as possible. This article will share more about how to test for kidney disease.

Stages of Kidney Disease

Kidney disease happens in stages. These stages help doctors determine how advanced the condition is by looking at a lab value called the GFR or the glomerular filtration rate.

The different stages of kidney disease are as follows:

• Stage 1: A standard or high GFR of > 90 mL/min
• Stage 2: Mild kidney disease; GFR of 60-89 mL/min
• Stage 3A: Moderate kidney disease; GFR of 45-59 mL/min
• Stage 3B: Moderate kidney disease GFR of 30-44 mL/min
• Stage 4: Severe kidney disease GFR of 15-29 mL/min
• Stage 5: End-stage kidney disease GFR < 15 mL/min

Kidney disease is common in people who have diabetes because diabetes causes irregularities in blood sugar. Chronically high blood sugar can damage the blood vessels and affect kidney function.

Kidney Disease Symptoms

Many people who experience kidney disease¹ may not be aware of the symptoms or have no visible signs. The symptoms of chronic kidney disease may vary depending on if you are in the earlier or later stages of this condition. The initial stages of kidney disease often will not present symptoms.

Later stages of kidney disease may cause the following symptoms:

• Poor appetite
• Unexplained weight loss
• Swelling in the hands and feet
• Difficulty breathing
• Tiredness
• Blood in the urine
• Increased need to pee
• Insomnia
• Itchy skin

Types of Kidney Tests

If your doctor is concerned about the health of your kidneys, they may order several different diagnostic tests to evaluate the health of your kidneys, including blood tests, urine tests, and imaging tests.

Blood Tests

Your doctor may conduct a kidney disease blood test, taking a small blood sample that is then sent to a lab where specific values are looked at and tested. Kidney-related blood tests include glomerular filtration rate (GFR), blood urea nitrogen (BUN), and creatinine.

• GFR measures how well the kidneys filter the blood. GFR can show how well the kidneys are working and how advanced kidney disease has progressed if it is present.
• BUN looks at the amount of urea nitrogen in the blood. Urea nitrogen is typically filtered out of the blood by the kidneys.
• Creatinine is another substance typically removed from the blood when the kidneys are healthy. Abnormal creatinine or nitrogen levels may be an indicator of improperly working kidneys.

Urine Tests

Your doctor may want to look at your urine sample to determine how healthy your kidneys are. Standard urine tests for kidney disease may include urine albumin, protein, and creatinine clearance tests.

• A urine albumin test looks for the albumin in the urine. Albumin is typically filtered out of the urine by the kidneys, so if it is present in the urine, this could indicate a kidney issue.
• A urine protein test can look for and isolate any foreign proteins in the urine to evaluate for kidney disease.
• Creatinine clearance tests can help identify the amount of creatinine in the urine with the amount found in the blood.

Imaging Tests

Imagining tests can give your doctor an idea of the visual status of your kidneys. If your doctor thinks imaging tests are needed, they may order an ultrasound, CT scan, or MRI. Imagining scans allow your doctor to look for kidney blockages and other abnormalities.

Kidney Disease Diet 

If your doctor does find that you have kidney disease, they will likely order you to begin after making adjustments to your diet. A Kidney Disease Diet may help support and replenish your body in the most beneficial way possible.

Foods that patients with kidney disease should avoid include:

• Salty foods such as canned food, cured meat, and fast food
• Potassium-rich foods; bananas, avocados, potatoes, and chocolate
• Sugary foods – candy and soda
• Foods high in phosphorus – nuts, beans, and whole-wheat bread
• Foods high in calcium – dairy products and canned fish
• Foods high in saturated and trans fat
• Alcoholic beverages

Foods that are okay to eat on a kidney disease diet include:

• Fresh fruit – berries, grapes, cherries, and apples
• Vegetables – cauliflower, onions, eggplant, and turnips
• Lean meats – eggs, poultry, and unsalted seafood
• White bread, pasta, bagels

Your doctor can help guide you through a kidney disease diet if needed. If kidney disease advances to the later stages, nutritional needs change. If you start to need dialysis, your body will require more protein, and you may also need to limit your fluid intake.

Last Words

Many different tests can help your doctor pinpoint the status of your kidneys. Kidney disease is diagnosed in stages, which gives an idea of how advanced the disease is and what treatment options are best. Early-stage kidney disease does not always show symptoms, so it is vital to get tested regularly.

A simple blood test for kidney disease can tell a lot about your kidney health. Consult with a medical professional regarding your testing options if you are concerned about the condition of your kidneys.

• In-Home Lab Tests
• Micronutrient Testing
• Heavy Metals Testing