---
title: "Ketones in urine levels: what trace to large means, the diet, fasting and pregnancy causes, and when ketones signal ketoacidosis"
type: biomarker
url: "https://www.test-well.com/biomarkers/ketones-in-urine"
also_known_as:
  - ketones in urine
  - urine ketones
  - ketones
  - ketones, ua
  - ketones, urine
  - ketonuria
  - acetoacetate, urine
category: Urinalysis
units:
  - mg/dL
order_price_usd: 17.99
order_item: Complete Urinalysis Test
order_url: "https://www.test-well.com/tests/urinalysis"
reviewed_at: 2026-11-03
---

# Ketones in urine levels: what trace to large means, the diet, fasting and pregnancy causes, and when ketones signal ketoacidosis

> Ketones in Urine is measured with a urine sample; no fasting is needed. At TestWell it's $17.99 all-in as Complete Urinalysis Test, results in 1–3 business days, drawn at Labcorp. An out-of-range result is a prompt to look closer, not a diagnosis.

Ketones appear in the urine whenever the body burns fat faster than it can use the fuel — after a night without food, on a low-carbohydrate diet, after a long workout, in early pregnancy and during a stomach bug. In those settings they are expected and harmless. The result that matters is moderate or large ketones with a high blood glucose, nausea, vomiting or rapid breathing, which is diabetic ketoacidosis and an emergency.

Also known as: ketones in urine, urine ketones, ketones, ketones, ua, ketones, urine, ketonuria, acetoacetate, urine.

## Key facts

| Fact | Value |
| --- | --- |
| Units | mg/dL |
| Sample | Urine sample |
| Fasting | Not required |
| Results | 1–3 business days |
| Price | $17.99 |
| Labs | Labcorp · BioReference in NY/NJ |

## What do ketones in urine measure?

When glucose is scarce or cannot get into cells, the liver converts fatty acids into three ketone bodies — beta-hydroxybutyrate, acetoacetate and acetone — that the brain, heart and muscles can burn instead. The urine dipstick detects acetoacetate (and acetone weakly) with a nitroprusside reaction and grades it negative, trace (about 5 mg/dL), small (15), moderate (40) and large (80–160 mg/dL).

It does not detect beta-hydroxybutyrate, which is the dominant ketone early in diabetic ketoacidosis. That creates two traps: the urine can under-read at the start of ketoacidosis, and it reads higher during recovery as beta-hydroxybutyrate is converted back to acetoacetate, so urine ketones lag behind the true picture in both directions. Blood ketone meters measure beta-hydroxybutyrate directly and are what diabetes guidelines now recommend for sick-day monitoring.

The urine value also depends on how concentrated the urine is and on timing — it reflects the hours since the bladder last emptied rather than the moment of the test — so it is a screening result that is confirmed, when it matters, with a blood glucose, a blood ketone and a metabolic panel.

## Who should check urine ketones?

People with type 1 diabetes, and anyone with diabetes taking an SGLT2 inhibitor (empagliflozin, dapagliflozin, canagliflozin, ertugliflozin), should check ketones whenever they are ill, vomiting, unable to eat, or have a blood glucose persistently above 250 mg/dL — and on SGLT2 inhibitors even when glucose is normal, because those drugs can cause euglycemic ketoacidosis. Children with diabetes are checked at any illness.

Pregnant women with severe nausea or hyperemesis are checked for ketones as a marker of starvation and dehydration; people on ketogenic diets sometimes test to confirm nutritional ketosis, although urine strips are an unreliable guide once the body adapts; and ketones appear on routine urinalyses after an overnight fast or a hard workout, where they usually need no action at all.

## How to get tested for ketones in urine and prepare

Urine ketones are part of a complete urinalysis, which can be ordered online through TestWell and collected as a walk-in urine sample at a Labcorp patient service center (the urinalysis with reflex to culture is also offered at Quest). Over-the-counter ketone strips give the same dipstick reading at home, and a blood ketone meter gives the beta-hydroxybutyrate level that diabetes care relies on.

For a routine check, collect a clean-catch sample when you have eaten normally in the previous 12 hours; a fasting or post-workout sample will show ketones for ordinary reasons. Use a fresh sample — acetoacetate breaks down and acetone evaporates, so a sample left standing reads falsely low — and tell the lab about captopril, mesna, N-acetylcysteine, levodopa or valproate, which can produce false positives, and about any low-carbohydrate diet.

## What is a normal ketones in urine result?

Negative. Trace to small ketones after an overnight fast, in the morning in pregnancy, after prolonged exercise or on a carbohydrate-restricted diet are expected and are not a disease. Moderate or large ketones should be explained: a long fast or vomiting illness in someone without diabetes, or ketoacidosis until proven otherwise in someone with diabetes.

The difference between nutritional ketosis and ketoacidosis is acid: blood beta-hydroxybutyrate runs 0.5–3 mmol/L in a well person on a ketogenic diet with a normal bicarbonate and pH, whereas diabetic ketoacidosis is defined by ketones with a bicarbonate below 18 mmol/L, a pH below 7.3 and a raised anion gap, usually with glucose above 250 mg/dL. Insulin keeps ketone production in check, so without diabetes the body rarely makes enough ketones to turn the blood acidic — alcoholic ketoacidosis after a binge with vomiting and starvation is the exception.

## What causes ketones in urine?

The everyday causes: fasting for more than 12–18 hours, a ketogenic or very-low-carbohydrate diet, prolonged or intense exercise, pregnancy (where fasting ketosis develops faster), vomiting or diarrhea with poor intake, crash dieting and eating disorders, acute illness with fever, and heavy alcohol use. In children, any febrile illness with reduced eating produces ketones readily.

The dangerous cause is diabetic ketoacidosis — insulin deficiency in type 1 diabetes (a missed dose, a pump failure, a new diagnosis), severe stress or infection in type 2 diabetes, and the euglycemic form on SGLT2 inhibitors where the glucose can be near normal. Alcoholic ketoacidosis and, rarely, isopropyl alcohol ingestion (which produces acetone) and some inborn errors of metabolism complete the list. Drugs can mimic ketones on the strip without any ketones being present — captopril, mesna, N-acetylcysteine, levodopa, valproate metabolites and strongly pigmented urine.

## What to check next when ketones show in urine

Start with the glucose. In someone with diabetes, moderate or large ketones with a glucose above 250 mg/dL — or any ketones with nausea, vomiting, abdominal pain, rapid breathing or drowsiness — means a blood ketone (beta-hydroxybutyrate), a basic metabolic panel for bicarbonate and the anion gap, and same-day or emergency care; follow your sick-day plan with extra insulin and fluids as instructed in the meantime. On an SGLT2 inhibitor, ketones in an unwell person are an emergency regardless of glucose. Without diabetes, eat and hydrate and repeat: small ketones from fasting, exercise or diet clear within hours of a carbohydrate-containing meal. Pregnant women with persistent ketones who cannot keep fluids down need assessment for hyperemesis and intravenous fluids. If ketones persist in someone eating normally, check glucose, hemoglobin A1c and a metabolic panel.

## What does a high Ketones in Urine mean?

Fasting, a ketogenic or very-low-carbohydrate diet, prolonged exercise, vomiting and pregnancy produce small to moderate ketones; large ketones with a high blood glucose, thirst, nausea or rapid breathing is diabetic ketoacidosis, an emergency.

## How do you get tested for Ketones in Urine?

| Order | Type | Price | Includes |
| --- | --- | --- | --- |
| [Urinalysis, Complete](https://www.test-well.com/tests/urinalysis) | Single test | $17.99 | This marker |
| [Kidney Health Panel](https://www.test-well.com/tests/kidney-health-panel) | Panel | $64.99 | 4 tests |
| [Early Pregnancy Panel](https://www.test-well.com/tests/prenatal-screening-panel) | Panel | $249.99 | 9 tests |
| [Men's Total Body Advanced Panel](https://www.test-well.com/tests/mens-total-body-advanced-panel) | Panel | $999.99 | 65 tests |
| [Women's Total Body Advanced Panel](https://www.test-well.com/tests/womens-total-body-advanced-panel) | Panel | $999.99 | 65 tests |

## Quest vs Labcorp vs BioReference

| Lab | Available | Price | Notes |
| --- | --- | --- | --- |
| Quest Diagnostics | No | — | Not offered through Quest for this test. |
| Labcorp | Yes | $17.99 | Choose Labcorp at checkout; walk-in patient service centers in every state TestWell serves outside NY and NJ. |
| BioReference (NY & NJ) | Yes | $20.99 | New York and New Jersey orders route here automatically — state rules keep Quest and Labcorp from accepting self-ordered draws. |

- [What a high Ketones in Urine means (causes, symptoms, next steps)](https://www.test-well.com/biomarkers/ketones-in-urine/high)

## Common questions about Ketones in Urine

### Are ketones in urine normal on a keto diet?

Yes. A ketogenic or very-low-carbohydrate diet is designed to produce ketones, and trace to moderate urine ketones are expected, especially in the first weeks. Urine strips become an unreliable guide after adaptation because the kidneys excrete less acetoacetate, so a blood ketone meter is better if you want to track nutritional ketosis. Ketones with nausea, vomiting or a high blood glucose are a different matter.

### What do small, moderate and large ketones mean?

Roughly 15, 40 and 80–160 mg/dL of acetoacetate. Trace and small are typical of fasting, exercise, pregnancy and low-carbohydrate eating; moderate and large should have an explanation. In diabetes, moderate or large ketones — particularly with a blood glucose above 250 mg/dL or any feeling of illness — are treated as ketoacidosis until a blood ketone and metabolic panel say otherwise.

### Can you have ketones in urine without diabetes?

Yes, commonly: after an overnight fast, on a ketogenic diet, after a long run, during a vomiting illness, in early pregnancy and after heavy drinking. Without diabetes, insulin keeps ketone production under control, so these rarely progress to acidosis; the exception is alcoholic ketoacidosis after a binge with vomiting and little food, which needs emergency care.

### Why are urine ketones negative when my blood ketones are high?

The urine dipstick detects acetoacetate but not beta-hydroxybutyrate, which is the main ketone early in diabetic ketoacidosis. A blood ketone meter measures beta-hydroxybutyrate directly and is the test diabetes guidelines recommend during illness. The opposite can also happen during recovery, when urine ketones stay positive after blood ketones have fallen.

### Do I need a doctor's order to test my ketones in urine?

No. TestWell's licensed physician network reviews and approves your order — usually within minutes. You can place an order online without an in-person visit or a referral from your own doctor.

### How long does it take to get Ketones in Urine results?

Most Ketones in Urine results are available in 1–3 business days after your specimen arrives at the lab. You'll get an email the moment your results are ready, with everything viewable in your TestWell portal.

### How much does a Ketones in Urine test cost?

Our Complete Urinalysis Test starts at $17.99. That's the all-in price — no copays, no insurance hoops, no surprise bills. HSA and FSA cards are accepted.

### Do I need to fast before my Ketones in Urine test?

Fasting is not required for the Ketones in Urine test. You can have your blood drawn any time of day.

### Which lab will process my Ketones in Urine test?

Your test will be processed by Quest Diagnostics, Labcorp, or BioReference depending on which is closest to you and which lab carries the test. All three are CLIA-certified and trusted by hospitals nationwide. You'll choose your lab during checkout from 4,000+ locations.

## Keep reading

- [A1c Levels Explained: Normal Ranges, Prediabetes Cutoffs, and What Can Skew Your Number](https://www.test-well.com/guides/a1c-levels-explained)
- [Metabolic Lab Testing: Which Panel Do You Actually Need?](https://www.test-well.com/guides/metabolic-lab-testing)
- [How to Read Your Blood Test Results, Line by Line](https://www.test-well.com/guides/how-to-read-your-blood-test-results)
- [Excessive thirst: which blood tests?](https://www.test-well.com/symptoms/excessive-thirst)
- [Nausea: which blood tests?](https://www.test-well.com/symptoms/nausea)
- [Frequent urination: which blood tests?](https://www.test-well.com/symptoms/frequent-urination)
- [Before your test: Fasting](https://www.test-well.com/prep/fasting)
- [Before your test: Keto and high-protein diets](https://www.test-well.com/prep/keto-and-high-protein-diets)
- [Before your test: Exercise](https://www.test-well.com/prep/exercise)

## Sources

- [MedlinePlus (NIH) — Ketones in Urine](https://medlineplus.gov/lab-tests/ketones-in-urine/)
- [American Diabetes Association — Standards of Care in Diabetes 2024: diabetic ketoacidosis](https://diabetesjournals.org/care/issue/47/Supplement_1)
- [Simerville JA, et al. Urinalysis: a comprehensive review. Am Fam Physician. 2005;71(6):1153–62](https://www.aafp.org/pubs/afp/issues/2005/0315/p1153.html)
- [Dhatariya KK, et al. Diabetic ketoacidosis. Nat Rev Dis Primers. 2020;6:40](https://pubmed.ncbi.nlm.nih.gov/32409703/)

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---

Medically reviewed by Youmna DiStefano, MD (Medical Reviewer, TestWell); last reviewed 2026-11-03. Review policy: https://www.test-well.com/reviewers/youmna-distefano-md

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