Evidence-Based Supplement & Herb Guides

Blood Urea Nitrogen (BUN) Test: Normal Range, High and Low Levels, and Kidney Health

Understand what a BUN blood test measures, common normal ranges, causes of high or low BUN, kidney-function meaning, dehydration effects, and how to interpret results with creatinine and eGFR.

A blood urea nitrogen (BUN) test measures the nitrogen portion of urea in the blood. Urea is a waste product made mainly in the...

BUN/Creatinine Ratio Test: High, Low, Dehydration, Kidney Function, and Meaning

Learn how to interpret a high or low BUN/creatinine ratio, what values around 10:1–20:1 mean, how dehydration affects the ratio, and why kidney function requires more than this single calculation.

The BUN/creatinine ratio compares two blood measurements that are commonly used when evaluating kidney function: blood urea nitrogen (BUN) and serum creatinine. The ratio...

Chronic Kidney Disease Blood Test Panel: eGFR, Creatinine, Cystatin C, BUN, and Monitoring

Understand the CKD blood test panel, including eGFR, creatinine, cystatin C, BUN, potassium, bicarbonate, urine albumin, CKD stages, and recommended monitoring intervals.

A chronic kidney disease (CKD) blood test panel is not one universal laboratory package. Instead, clinicians combine several tests to estimate kidney filtration, check...

Comprehensive Metabolic Panel (CMP) Test: Kidney, Liver, Electrolytes, Proteins, and Results

Learn what a comprehensive metabolic panel (CMP) measures, how kidney, liver, electrolyte, protein, glucose, and calcium results are interpreted, and when abnormal values need follow-up.

A comprehensive metabolic panel (CMP) is a group of 14 blood measurements that gives a broad snapshot of kidney function, liver-related markers, electrolytes, blood...

Creatinine Blood Test: Normal Range, High and Low Levels, and Kidney Function

Understand creatinine blood test ranges, why creatinine can be high or low, how muscle mass and hydration affect results, and how creatinine relates to eGFR and kidney function.

A creatinine blood test measures the amount of creatinine in your bloodstream and is one of the most common ways to assess kidney filtration....

Creatinine Clearance Test: Kidney Filtration, Blood and Urine Collection, and Results

Learn how a creatinine clearance test uses blood and 24-hour urine creatinine to estimate kidney filtration, what high or low results mean, and how it differs from eGFR and measured GFR.

A creatinine clearance test estimates how much blood the kidneys clear of creatinine each minute by comparing creatinine in a timed urine collection with...

Cystatin C Blood Test: High Levels, eGFR, Kidney Function, and Heart Risk

Learn what a cystatin C blood test measures, why levels can be high, how cystatin C compares with creatinine, how it improves eGFR accuracy, and what its association with heart risk means.

A cystatin C blood test measures a small protein produced by nearly all nucleated cells and cleared from the bloodstream mainly by the kidneys....

eGFR With Cystatin C Test: Kidney Filtration, Accuracy, Creatinine Comparison, and Meaning

Learn how eGFR with cystatin C estimates kidney filtration, why combined creatinine-cystatin C equations improve accuracy, what discordant results mean, and when more precise kidney testing is useful.

An eGFR with cystatin C test estimates kidney filtration using the blood level of cystatin C, either alone or together with creatinine. The combined...

Kidney Failure Blood Test Panel: Creatinine, BUN, eGFR, Potassium, and Warning Signs

Learn how a kidney failure blood test panel uses creatinine, BUN, eGFR, potassium, bicarbonate, and other markers, plus which warning signs and complications may require urgent care.

A kidney failure blood test panel is not one single standardized test. It is a practical group of blood measurements used to determine how...

Kidney Function Blood Test Panel: eGFR, Creatinine, BUN, Cystatin C, and What They Mean

Understand a kidney function blood test panel, including eGFR, creatinine, BUN, cystatin C, potassium, and bicarbonate, plus how the results fit together and what follow-up testing may be needed.

A kidney function blood test panel combines several measurements that help show how well the kidneys filter blood and whether complications of reduced kidney...

Kidney Injury Molecule-1 (KIM-1) Blood Test: Kidney Tubule Damage Marker and Meaning

A KIM-1 blood test measures a kidney tubule injury marker. Learn what high levels may mean, why cutoffs vary, and how KIM-1 compares with creatinine and eGFR.

Kidney injury molecule-1 (KIM-1) is a protein that rises when cells in the kidney’s proximal tubules are injured. A KIM-1 blood test measures the...

Neutrophil Gelatinase-Associated Lipocalin (NGAL) Blood Test: Kidney Injury Marker and Meaning

Learn what an NGAL blood test measures, why high levels can signal kidney injury, how inflammation affects results, and how NGAL compares with creatinine and eGFR.

Neutrophil gelatinase-associated lipocalin (NGAL), also called lipocalin-2, is a small protein that can rise rapidly in blood after kidney tubule injury. Researchers and some...

Parathyroid Hormone (PTH) Test in Kidney Disease: Calcium, Phosphorus, CKD-MBD, and Meaning

Learn how to interpret a PTH test in kidney disease, including high and low PTH, calcium and phosphorus balance, CKD-MBD, dialysis targets, and follow-up.

A parathyroid hormone (PTH) blood test is an important part of monitoring chronic kidney disease because the kidneys, parathyroid glands, bones, calcium, phosphorus, and...

Potassium Blood Test in Kidney Disease: High Levels, Low Levels, Heart Risk, and Meaning

Learn how to interpret a potassium blood test in kidney disease, including high and low levels, heart risk, false highs, medication causes, diet, and urgent warning signs.

A potassium blood test measures the amount of potassium circulating in the blood. In kidney disease, it is one of the most important safety...

Renal Function Panel Test: Kidney Markers, Electrolytes, Minerals, and Result Meaning

Learn what a renal function panel tests, including creatinine, eGFR, BUN, electrolytes, calcium, phosphorus, albumin, common result patterns, and kidney meaning.

A renal function panel is a group of blood tests used to assess kidney filtration and the body systems the kidneys help regulate. Although...

Symmetric Dimethylarginine (SDMA) Test: Kidney Function, High Levels, and Early Kidney Disease

Learn how the SDMA blood test relates to kidney function, what high SDMA can mean, its potential role in early kidney disease, and how it compares with creatinine and eGFR.

Symmetric dimethylarginine (SDMA) is a small molecule released when the body breaks down proteins that contain methylated arginine. Much of circulating SDMA is cleared...