A flag on your metabolic panel is common, but some results deserve a closer look

Key takeaways

• Lab ranges are generally built to hold the middle 95% of healthy people’s results, so by our rough math a healthy person could face close to even odds of at least one flag on a 14-test panel¹³.
• In a 1994 study of 8,818 Oklahoma state health plan members, 54% of those with a lab flag had none left once the ranges were rebuilt from the healthiest participants¹.
• About 14% of U.S. adults, roughly 37 million people, had chronic kidney disease in 2021–2023 survey data, and about 87% of adults with it didn’t know, the CDC estimates⁶.
• Kidney disease is judged by two tests, a blood eGFR and a urine albumin test, and the urine test isn’t part of the standard panel³⁸.
• A normal ALT doesn’t rule out fatty liver disease, and a mildly high one has many causes, so a liver result that stays high is the one to follow up¹¹¹².

In early 1994, Oklahoma’s health plan for state and school employees made members an offer. Adults over 25 could get a 25-test blood chemistry panel and a cholesterol check for $15¹.

From February 1 to March 15, 8,818 people had blood drawn at about 300 sites around the state. Researchers at the University of Oklahoma Health Sciences Center then studied 20 of the tests¹. About half the people, 4,498 of them, had at least one value outside the lab’s normal range¹.

Next, the team rebuilt the normal ranges from 270 of the healthiest participants. These were people with no related diseases, no recent blood pressure or thyroid medicines and top scores on a health questionnaire¹.

By those ranges, 54% of the flagged people had no flags left. Meanwhile, a third of the people with clean reports now had at least one¹.

“Normal,” in other words, depends on who was measured to draw the line. This guide decodes the comprehensive metabolic panel, the kidney and liver numbers that matter most for heart and metabolic health, and the extras people ask about.

A normal range is built to leave out 1 in 20 healthy people

A lab’s reference range is generally assumed to hold the middle 95% of results from a group of healthy people¹. So on any one test, about 1 healthy person in 20 lands outside it by design.

Run many tests and the odds stack up. The Oklahoma team gave the formula: the chance of at least one flag is 1 minus 0.95 raised to the number of tests¹. For a 14-test panel, by our math, that’s about 51%.

The real figure differs, because the tests rise and fall together rather than independently, as the authors noted¹. Still, MedlinePlus, the National Library of Medicine’s consumer health site, says healthy people land outside a range fairly often².

Everyday life can nudge a number, too. A tough workout before the blood draw, your period, a new pill or supplement, a recent meal or drink, or a fast you didn’t finish can all show up in results, MedlinePlus explains². Methods and ranges vary from lab to lab, so read each number against the range printed beside it².

The reference group matters, too. In the Oklahoma data, the upper limit for ALT, a liver enzyme, was 70 among heavier participants and 49 among lighter ones¹. A range drawn from a less healthy crowd can make a high-ish value look fine.

And it works the other way: a normal result doesn’t guarantee good health². Our articles on out-of-range results and single flagged numbers cover the general logic. Here we focus on the metabolic markers.

The 14 numbers on a comprehensive metabolic panel

A comprehensive metabolic panel, or CMP, is a standard blood chemistry test. It measures 14 things³:

• Glucose, your blood sugar.
• Calcium.
• Four electrolytes: sodium, potassium, chloride and carbon dioxide (bicarbonate).
• Two blood proteins: albumin and total protein.
• Three enzymes and bilirubin that reflect liver health: ALP, ALT and AST.
• Two kidney markers: blood urea nitrogen (BUN) and creatinine.

Your report may also show an eGFR, a kidney estimate calculated from creatinine, age and sex⁷. MedlinePlus advises nothing to eat or drink for at least 8 hours before a CMP, but follow your own lab’s instructions³.

The metabolic panel decoder

We built this table from the sources cited. The ranges are MedlinePlus examples, so use the range printed on your own report³.

Line	What it measures	Example range	Common reasons it’s off	What to ask
Glucose	Blood sugar	70–100 mg/dL3	Not fasting 8 hours; a fasting 100–125 is the prediabetes range14	“Was I fasting long enough? Should we check an A1C?”
Sodium	An electrolyte	135–145 mEq/L3	Dehydration, vomiting or diarrhea, water pills, some pain relievers and antidepressants4	“Could a medicine or recent illness explain this?”
Potassium, chloride, CO2	Other electrolytes and acid balance	3.7–5.2; 96–106; 23–293	Medicines, supplements, food and hard exercise can shift results2	“Is this worth repeating?”
Calcium	Calcium, about half of it carried on proteins	8.5–10.2 mg/dL3	Parathyroid problems, too much or too little vitamin D, kidney disease, low blood protein5	“Was my albumin low, too?”
Albumin, total protein	Blood proteins	3.4–5.4; 6.0–8.3 g/dL3	Dehydration raises albumin; liver or kidney disease, poor nutrition and infection lower it9	“Do my other results point anywhere?”
ALP, ALT, AST, bilirubin	Liver enzymes and bilirubin; AST also comes from muscle11	ALT 4–36; AST 8–33 U/L3	Fatty liver, alcohol, medicines, supplements, hard exercise1011	“Has it stayed high? Can we calculate my FIB-4?”
BUN, creatinine	Waste products the kidneys filter	BUN 6–20; creatinine 0.6–1.3 mg/dL3	Muscle mass, a vegetarian diet (lower), a recent cooked-meat meal (higher)7	“What’s my eGFR? Should we add a urine test or cystatin C?”

Kidney numbers: creatinine, eGFR and the urine test the panel skips

Creatinine is a waste product your muscles make all day and your kidneys filter out. Because muscle sets the supply, the National Kidney Foundation (NKF) notes that very low or very high muscle mass, an amputation, a vegetarian diet or a recent cooked-meat meal can all shift it⁷. Our creatine article explains why that supplement can push the number up.

Labs turn creatinine, age and sex into an eGFR, an estimate of how much blood your kidneys filter per minute. Since 2021, the NKF and the American Society of Nephrology have recommended an equation that leaves out race⁷. Compared with the old version, it gives lower numbers for Black people and higher numbers for others with the same creatinine⁷.

What’s normal? Young adults run about 120, and the number falls with age⁷. A result of 90 or more is normal for most healthy young people, and 60 to 89 can be normal for some older adults⁷. Below 60 for three months or longer meets the definition of chronic kidney disease, even with no other sign of damage⁷.

The international kidney guideline group KDIGO (Kidney Disease: Improving Global Outcomes) uses the same yardstick in its 2024 guideline: abnormal kidney structure or function lasting more than three months⁸. It grades kidney disease two ways, by filtering and by albumin, a protein that leaks into urine when the kidney’s filters are damaged⁸.

That second test is a urine albumin-to-creatinine ratio, or uACR, and it isn’t one of the panel’s 14³. KDIGO treats a result under 30 mg/g as below significant albumin loss⁸. If you have diabetes or high blood pressure, it’s worth asking about: the CDC estimates that 38% of adults with diabetes and 21% with high blood pressure have kidney disease⁶.

Kidney numbers wobble. KDIGO says an eGFR change of more than about 20% likely reflects a real shift; smaller moves can be random⁸. By our math, an eGFR that slips from 70 to 60 is a 14% drop, inside that band. Urine albumin has to fall by more than half or double before a change is likely real⁸.

When creatinine may mislead, a second marker can help. Cystatin C, a protein made by nearly all cells, varies less with age, sex and diet⁷. Combined with creatinine, it gives a more accurate eGFR than either alone⁷⁸.

Kidney disease often goes unnoticed. About 14% of American adults, roughly 37 million, had kidney disease in 2021–2023 national data, and about 87% of them didn’t know, the CDC reported in March 2026⁶. The rate was 34% at 65 and older⁶. The CDC adds that its one-time-test estimates may overstate the total⁶.

Kidneys and heart travel together. KDIGO advises estimating 10-year heart risk with a tool that includes kidney tests, such as the American Heart Association’s PREVENT equations⁸.

Liver numbers: ALT, AST and the fatty liver that often hides

Somewhere between 1 in 10 and 1 in 5 people have a raised liver test, a 2024 review in American Family Physician reports¹¹. Doctors call a rise mild when it runs from double up to five times the top of the normal range¹¹.

ALT points more specifically to the liver. AST is also made in the heart, other muscles, the kidneys and the brain¹¹. A 2017 review in American Family Physician adds that an AST-to-ALT ratio above 2 suggests alcohol-related liver disease¹⁰.

The most common causes of a mild rise are fatty liver tied to metabolic problems, now called MASLD (metabolic dysfunction-associated steatotic liver disease), and alcohol-related liver disease¹¹. In earlier studies, fatty liver explained 25% to 51% of ALT or AST rises in people without symptoms¹⁰. A 2020 review estimated it affects up to 30% of U.S. adults¹².

How high is high? The 2017 review cites the American College of Gastroenterology’s healthy ALT as 29 to 33 for men and 19 to 25 for women¹⁰. MedlinePlus’s example range runs up to 36³. So a woman with an ALT of 32 could see “normal” on a report using that range and still sit above the gastroenterologists’ healthy band.

The bigger catch: “Liver enzyme levels are often normal in patients with NAFLD,” the older name for fatty liver disease, a 2020 review in American Family Physician notes¹². A clean liver line doesn’t clear you.

For people at higher risk, a 2024 review recommends a scarring score called FIB-4 or a similar tool¹¹. FIB-4 uses your age, AST, ALT and platelet count¹². Platelets come from a blood count, not the CMP, so ask whether yours was done.

Repeating a mildly high result isn’t required at the start of a workup¹⁰. In one UK group, 84% of abnormal results were still abnormal a month later¹⁰. What calls for more testing is a rise that persists or any sign of liver disease¹¹. Bring a list of medicines and supplements, since both can raise liver enzymes¹¹.

Glucose, insulin and uric acid: what the panel shows and what it doesn’t

Glucose. The CMP’s glucose counts as a fasting result only if you went at least 8 hours with nothing but sips of water, says the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)¹⁴. The A1C, a longer-term sugar average, is a separate test. If the two don’t agree, NIDDK says, the A1C may not be reliable for you¹⁴. Our blood glucose article covers the cutoffs and the A1C’s blind spots.

Fasting insulin. It’s not on the CMP³. NIDDK says the test for insulin resistance is mainly a research tool¹⁵. A companion article on insulin resistance explains the proxies people ask about.

Uric acid. This is the waste product behind gout, and it isn’t on the CMP either³. About 3.9% of U.S. adults had gout in 2015–2016: 5.2% of men and 2.7% of women¹³. Risk rises with meat- and seafood-heavy eating, sugary drinks and fruit juice, beer, some water pills, kidney disease and obesity¹³. In the Oklahoma data, uric acid ran higher in heavier people¹.

Two surprises. Uric acid can fall during a gout attack: in pooled trial data, 14% of patients measured below 6 mg/dL mid-flare¹³. And although gout travels with heart disease, diabetes and kidney disease, a meta-analysis found no evidence that uric-acid-lowering drugs cut heart events¹³.

How strong is the evidence?

Claim	Evidence rating	What it rests on
A blood eGFR plus urine albumin identifies chronic kidney disease	Strong evidence	KDIGO 2024 definition and NKF guidance78
Adding cystatin C makes eGFR more accurate	Strong evidence	NKF and KDIGO78
Weight loss reduces fatty liver	Strong evidence for less liver fat	3% to 5% loss improves fat; 7% to 10% improves liver tissue12
Fasting insulin is a reliable routine test	Not enough evidence	NIDDK: mainly used in research15
One flag on a large panel usually means disease	Evidence says no, or unsafe	95% design; the Oklahoma study12
A normal ALT rules out fatty liver	Evidence says no, or unsafe	Enzymes are often normal in fatty liver12
Lowering uric acid with drugs prevents heart attacks	Evidence says no, or unsafe	A meta-analysis found no evidence of fewer heart events13

Your panel is a report card your habits can move

Natural-health readers often want proof that their choices are working. A metabolic panel can supply some of it, if you read it over time.

Several of these numbers answer to daily habits. Losing 3% to 5% of body weight improves fatty liver, and 7% to 10% improves the liver tissue itself¹². Gout risk tracks sugary drinks, beer and heavy meat and seafood eating¹³.

Some shifts look worse than they are. A very muscular person may carry higher creatinine, and a vegetarian lower creatinine, because of muscle and diet⁷. Neither number tells the whole kidney story alone.

Because labs differ, compare your results with your own past results from the same lab². A steady creatinine and a falling ALT say more than any single flag.

Questions readers ask

The bottom line

A routine metabolic panel is designed so that healthy people sometimes land outside the lines. A single flag, especially a small one, is often just math or a recent meal. Patterns matter more: an eGFR that stays below 60, urine albumin that keeps showing up, or a liver enzyme that stays high.

Ask for the kidney urine test if you have diabetes or high blood pressure, and remember that normal liver enzymes can miss fatty liver. Track your own numbers at the same lab over time. Bring questions, not panic, to your clinician.

Related reading

• Why being out of range often means nothing at all
• Why one flagged lab number is not a diagnosis
• Creatine Helps Short, Hard Efforts. Its Hair and Kidney Scares Rest on Thin Evidence
• Your cholesterol panel leaves out two numbers that matter: ApoB and Lp(a)
• Heart scan packages mostly sell tests experts don’t back, and the best checks are routine

Sources

1. Mold JW, Aspy CB, Blick KE, Lawler FH. “The Determination and Interpretation of Reference Intervals for Multichannel Serum Chemistry Tests.” Journal of Family Practice, 1998;46(3):233–241. pubmed.ncbi.nlm.nih.gov
2. MedlinePlus. “How to Understand Your Lab Results.” National Library of Medicine, updated September 4, 2025. medlineplus.gov
3. MedlinePlus Medical Encyclopedia. “Comprehensive metabolic panel.” National Library of Medicine, reviewed January 1, 2025. medlineplus.gov
4. MedlinePlus. “Sodium Blood Test.” National Library of Medicine, updated December 2, 2024. medlineplus.gov
5. MedlinePlus. “Calcium Blood Test.” National Library of Medicine, updated December 2, 2024. medlineplus.gov
6. Centers for Disease Control and Prevention. “Chronic Kidney Disease in the United States.” CDC, updated March 2026. cdc.gov
7. National Kidney Foundation. “Frequently Asked Questions About GFR Estimates.” NKF, 2022. kidney.org
8. Kidney Disease: Improving Global Outcomes (KDIGO). “KDIGO 2024 CKD Guideline: Top 10 Takeaways for Primary Care Providers, Evaluation.” KDIGO, 2024. kdigo.org
9. MedlinePlus. “Albumin Blood Test.” National Library of Medicine, updated December 9, 2024. medlineplus.gov
10. Oh RC, Hustead TR, Ali SM, Pantsari MW. “Mildly Elevated Liver Transaminase Levels: Causes and Evaluation.” American Family Physician, 2017;96(11):709–715. aafp.org
11. Langan RC, Hines-Smith KA. “Mildly Elevated Liver Transaminase Levels: Causes and Evaluation.” American Family Physician, 2024;110(6):585–591. aafp.org
12. Westfall EC, Jeske R, Bader AR. “Nonalcoholic Fatty Liver Disease: Common Questions and Answers on Diagnosis and Management.” American Family Physician, 2020;102(9):603–612. aafp.org
13. Clebak KT, Morrison A, Croad JR. “Gout: Rapid Evidence Review.” American Family Physician, 2020;102(9):533–538. aafp.org
14. National Institute of Diabetes and Digestive and Kidney Diseases. “Diabetes Tests & Diagnosis.” NIDDK, last reviewed July 2022. niddk.nih.gov
15. National Institute of Diabetes and Digestive and Kidney Diseases. “Insulin Resistance & Prediabetes.” NIDDK, last reviewed March 2025. niddk.nih.gov