Kidney Function Test, Serum

Kidney Function Test, Serum

What it is

The Kidney Function Test (KFT), Serum is a panel of blood tests that measure key markers to assess how well the kidneys are filtering and removing waste from the body. Common components include serum creatinine, blood urea nitrogen (BUN), uric acid, electrolytes (sodium, potassium, chloride), and estimated glomerular filtration rate (eGFR). Together, these markers provide an overview of kidney health and detect early signs of kidney disease or damage.

Uses

This test is used to diagnose and monitor chronic kidney disease (CKD), evaluate kidney performance in people with diabetes or hypertension, and check for kidney-related complications. It may also be ordered to monitor the effects of medications that can affect kidney function, or before surgeries and major treatments to ensure kidney health.

Symptoms That May Lead to the Test

Doctors may recommend this test if you have swelling in the legs or face, reduced urine output, frequent urination, foamy or bloody urine, persistent fatigue, high blood pressure, nausea, or unexplained weight loss. It is especially important for patients with risk factors such as diabetes, hypertension, or a family history of kidney disease.

Abnormal Results

Elevated Creatinine and BUN: Suggest reduced kidney function, dehydration, or kidney disease.

Low eGFR: Indicates reduced filtration capacity of the kidneys, often a sign of chronic kidney disease.

Electrolyte Imbalances: Abnormal sodium, potassium, or chloride levels may suggest kidney dysfunction, metabolic imbalance, or dehydration.

High Uric Acid: May indicate kidney dysfunction, gout, or conditions that reduce uric acid clearance.

Risks

The test requires a simple blood draw, which carries minimal risks such as mild pain, bruising, or dizziness at the puncture site. Serious complications are extremely rare.