Lab result explainedUrinalysisLast updated November 10, 2026

Protein in urine: the normal range, what trace, 1+, 2+ and 3+ protein mean, and causes

Protein in urine · Urinalysis (dipstick); urine protein-creatinine ratio; 24-hour urine protein · reported in Dipstick: negative, trace, 1+ to 4+ (approximate mg/dL); ratios in mg/g or g/g creatinine; 24-hour collection in mg or g per day

Protein in urine (proteinuria) means the kidney's filters are letting through more protein, mainly albumin, than they should, and a urine dipstick is the usual way it is first noticed. The normal result is negative or, at most, trace. Healthy kidneys let fewer than 150 mg of protein a day into urine (under 30 mg of albumin), which is too little for a dipstick to detect. The two most common reasons for a positive result are a temporary one, such as fever, hard exercise, dehydration, a urinary infection or standing for long periods, and a persistent one, such as diabetes, high blood pressure or kidney disease.

Dipstick results are graded trace (about 15 to 30 mg/dL), 1+ (30), 2+ (100), 3+ (300) and 4+ (1,000 mg/dL or more). Trace or 1+ on a single sample, especially a concentrated one, is often nothing, and the first step is simply to repeat it on a first-morning sample. Persistent 1+ or anything 2+ and above is measured properly with a urine protein-to-creatinine ratio (normal under 0.15 to 0.2 g/g) or an albumin-to-creatinine ratio (normal under 30 mg/g), which correct for how dilute the urine is.

In pregnancy, protein in urine is checked at every visit because, after 20 weeks, 300 mg or more a day (a protein-creatinine ratio of 0.3 or above) together with new high blood pressure defines preeclampsia. Outside pregnancy, persistent protein is the earliest sign of diabetic and hypertensive kidney damage and the most important predictor of whether kidney disease will progress, which is why finding it early and lowering it matters more than most people realise.

Protein in urine at a glance

  • What it is: protein, mainly albumin, leaking through the kidney filters into urine; detected first by dipstick and measured by a protein-to-creatinine or albumin-to-creatinine ratio.
  • Normal range: dipstick negative (trace at most); under 150 mg of protein per 24 hours; protein-creatinine ratio under 0.15–0.2 g/g; albumin-creatinine ratio under 30 mg/g. Labs differ.
  • Trace or 1+ (30 mg/dL) on one sample is often temporary (exercise, fever, dehydration, infection, standing); repeat on a first-morning sample before worrying.
  • Persistent 1+ or more, 2+ (100 mg/dL) and above, or a ratio above 0.2 g/g suggests kidney damage from diabetes, high blood pressure or glomerular disease and needs a proper work-up.
  • Nephrotic range is more than 3.5 g a day (ratio above 3–3.5), usually with swelling and low blood albumin. In pregnancy, 300 mg a day or a ratio of 0.3 or more with high blood pressure after 20 weeks is preeclampsia.
  • Next step: repeat on a first-morning clean-catch sample, then an albumin-creatinine or protein-creatinine ratio, creatinine and eGFR, blood pressure and glucose; a kidney specialist if protein persists or kidney function is reduced.

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What Protein in urine measures

Each kidney filters about 180 liters of blood a day through a million glomeruli, tiny capillary tufts whose walls are built to hold back proteins while letting water and waste through. The small amount of protein that does cross is mostly reabsorbed by the tubules, so healthy urine contains under 150 mg a day: a little albumin, some uromodulin from the tubules and traces of immunoglobulin light chains. Protein appears in excess when the glomerular wall is damaged (glomerular proteinuria, mostly albumin), when the tubules cannot reabsorb it (tubular proteinuria, smaller proteins), or when so much of a small protein is in the blood that the filters are overwhelmed (overflow proteinuria, as in myeloma).

The dipstick pad contains tetrabromophenol blue, a dye that changes from yellow to green to blue when protein binds to it. It is sensitive mainly to albumin, detecting about 10 to 20 mg/dL, and reads other proteins poorly, which is why myeloma light chains can give a negative strip despite grams of protein a day. Because the pad measures concentration, the same daily leak reads 3+ in concentrated morning urine and trace in dilute afternoon urine. The ratio tests fix this by dividing urine protein or albumin by urine creatinine in a single spot sample, which tracks the 24-hour excretion closely enough that 24-hour collections are now rarely needed.

Strips give false positives in alkaline urine (pH above 8), very concentrated urine, gross blood, heavy pyuria, semen, vaginal discharge, and after chlorhexidine or benzalkonium antiseptics or iodinated contrast dye. They give false negatives in very dilute urine and with non-albumin proteins. The albumin-creatinine ratio is the test guidelines now prefer for screening in diabetes, hypertension and chronic kidney disease, because it detects the 30 to 300 mg/g range (once called microalbuminuria) that the dipstick misses and that marks the earliest, most reversible stage of kidney damage.

Normal range for Protein in urine

Reference ranges vary between labs and by age, sex and pregnancy. Use the range printed on your own report.

GroupTypical range (Dipstick: negative, trace, 1+ to 4+ (approximate mg/dL); ratios in mg/g or g/g creatinine; 24-hour collection in mg or g per day)Notes
Dipstick negativeUnder about 10–15 mg/dLNormal. The expected result in a well-hydrated healthy adult.
Dipstick traceAbout 15–30 mg/dLUsually normal, particularly in concentrated or first-morning urine, after exercise or with fever. Repeat; quantify if it persists.
Dipstick 1+About 30 mg/dLMildly positive. Often transient or orthostatic in young people; persistent 1+ on two of three samples needs a ratio test and kidney function tests.
Dipstick 2+About 100 mg/dLSignificant. Rarely explained by dilution or exercise alone; quantify with a ratio and check creatinine, eGFR, blood pressure and glucose. In pregnancy after 20 weeks with high blood pressure, this level supports preeclampsia.
Dipstick 3+ to 4+300 to 1,000 mg/dL or moreHeavy proteinuria, often in the nephrotic range. Needs prompt assessment for glomerular disease, diabetic kidney disease or preeclampsia.
24-hour urine proteinUnder 150 mg/day normal; 150–500 mild; 500–3,500 moderate; above 3,500 mg/day nephrotic rangePregnancy: under 300 mg/day is normal; 300 mg or more with new hypertension after 20 weeks defines preeclampsia. Children: under 4 mg per square metre per hour.
Urine protein-creatinine ratio (UPCR)Under 0.15–0.2 g/g normal; 0.2–3.0 abnormal; above 3.0–3.5 g/g nephrotic rangeSpot sample, any time of day. In pregnancy a ratio of 0.3 or above is the threshold for preeclampsia proteinuria.
Urine albumin-creatinine ratio (UACR)Under 30 mg/g normal (A1); 30–300 moderately increased (A2); above 300 severely increased (A3)KDIGO categories. The preferred screening test in diabetes and hypertension; confirmed on two of three samples over 3 to 6 months.
Orthostatic (postural) proteinuriaProtein present in daytime samples, absent in first-morning sample; usually under 1 g/dayBenign condition of adolescents and young adults under 30; diagnosed with a split day/night collection.

High protein in urine (proteinuria)

A positive dipstick means more protein than usual is reaching the urine, but a single result rarely tells you why. Transient proteinuria is common: about 4 percent of men and 7 percent of women have protein on a random dipstick, and in most it is gone on repeat. Fever, vigorous exercise, dehydration, cold exposure, emotional stress, heart failure, seizures and urinary infection all raise it for a day or two. Young, slim adults frequently have orthostatic proteinuria, in which protein appears after hours upright and vanishes overnight; it affects 2 to 5 percent of adolescents, is confirmed with a first-morning sample that is negative, and has an excellent long-term outlook.

Persistent proteinuria, present on two of three samples taken weeks apart, means the kidney filter or tubules are damaged. By far the most common causes in adults are diabetes and high blood pressure, which together account for most chronic kidney disease. The amount matters: an albumin-creatinine ratio of 30 to 300 mg/g signals early, often reversible, damage and roughly doubles cardiovascular risk independent of kidney function; above 300 mg/g, or a protein-creatinine ratio above 1 g/g, predicts faster loss of kidney function and is the level at which specialist referral is standard. Nephrotic-range protein (more than 3.5 g a day) with swelling, a low blood albumin and high cholesterol means the glomerulus itself is diseased: minimal change disease, focal segmental glomerulosclerosis, membranous nephropathy, diabetic nephropathy, lupus nephritis or amyloidosis, and usually leads to a kidney biopsy.

Two patterns deserve particular attention. Protein with blood in the urine, especially with red-cell casts, suggests glomerulonephritis, which can progress quickly and is assessed promptly. And protein appearing in pregnancy after 20 weeks together with a blood pressure of 140/90 mmHg or higher is preeclampsia until proven otherwise, a condition that can threaten both mother and baby and needs same-day assessment; protein found before 20 weeks points to pre-existing kidney disease rather than preeclampsia.

Common causes

  1. Transient causes: fever, exercise, dehydration, cold, stress

    Any of these can push protein to trace or 1+, occasionally 2+, for 24 to 48 hours through changes in kidney blood flow. A repeat first-morning sample when well is negative. Marathon runners commonly show 1+ to 2+ protein for a day afterwards.

  2. Orthostatic (postural) proteinuria

    Protein leaks only when upright, probably from pressure on the left renal vein; total excretion is under 1 g a day and the first-morning sample is clear. Common in adolescents and adults under 30, benign and needs no treatment.

  3. Diabetic kidney disease

    The leading cause of persistent proteinuria. High glucose damages the glomerular filter over years; an albumin-creatinine ratio of 30 to 300 mg/g is the earliest sign, which is why people with diabetes are screened yearly. Up to 40 percent of people with diabetes develop it.

  4. High blood pressure (hypertensive nephrosclerosis)

    Sustained high pressure scars the small kidney arteries and glomeruli, producing low-grade proteinuria (usually under 1 g a day) and slowly falling eGFR. Controlling blood pressure to under 130/80 mmHg reduces both.

  5. Glomerulonephritis and nephrotic syndrome

    Immune or inflammatory damage to the glomerulus: IgA nephropathy (protein with blood after a sore throat), minimal change disease (nephrotic syndrome in children), FSGS, membranous nephropathy, lupus nephritis and post-infectious glomerulonephritis. Heavy protein, red-cell casts or a rising creatinine usually leads to a kidney biopsy.

  6. Preeclampsia

    After 20 weeks of pregnancy, new high blood pressure (140/90 mmHg or above) with 300 mg or more of protein a day or a protein-creatinine ratio of 0.3 or above. Can progress to seizures (eclampsia), liver and clotting problems; delivery is the only definitive treatment.

  7. Urinary tract infection, blood or contamination in the sample

    White cells, bacteria, red cells, semen, vaginal discharge and menstrual blood all add protein to the sample; the dipstick also reads falsely positive in alkaline urine (pH above 8) and after antiseptic washes or contrast dye. Treat the infection or repeat with a clean catch and the protein often disappears.

  8. Heart failure, obesity and sleep apnea

    Raised venous pressure and glomerular hyperfiltration from excess body weight cause low-grade albuminuria that improves with treatment of the heart failure, weight loss and CPAP.

  9. Multiple myeloma and amyloidosis (overflow proteinuria)

    Abnormal light chains flood the filter; the dipstick, which reads albumin, may be negative or only trace while a 24-hour collection or protein electrophoresis shows grams of protein. Suspected in people over 50 with anemia, bone pain, high calcium or an unexplained high creatinine.

  10. Medications and toxins

    NSAIDs, lithium, gold, penicillamine, some chemotherapy (bevacizumab, cisplatin), heroin and heavy metals can damage the glomerulus or tubules. NSAIDs can cause both interstitial nephritis and, less often, nephrotic syndrome.

Symptoms that can go with it

  • Usually none; most proteinuria is found on a routine or screening test
  • Foamy or frothy urine that persists after flushing (with heavier protein loss)
  • Swelling of the ankles, feet, hands or around the eyes, especially in the morning (nephrotic range)
  • Weight gain from fluid, breathlessness or reduced urine output
  • High blood pressure, headache or visual disturbance (in pregnancy, warning signs of preeclampsia)
  • Pink, red or cola-colored urine (glomerulonephritis, with blood)
  • Thirst, frequent urination, blurred vision or numb feet in undiagnosed or poorly controlled diabetes
  • Fatigue, nausea, itching or loss of appetite with advanced kidney disease

Read it alongside

  • Urine albumin-creatinine ratio (UACR) — the most sensitive and specific measure; 30 to 300 mg/g is moderately increased, above 300 severely increased, and it is the number used to stage kidney disease and guide treatment.
  • Creatinine and eGFR — tell you how well the kidneys are filtering; proteinuria with a falling eGFR is kidney disease that is progressing and needs specialist input.
  • Blood in urine and red-cell casts — protein plus blood, particularly with casts, points to glomerulonephritis rather than diabetic or hypertensive damage.
  • Albumin (blood) and lipid panel — a low serum albumin (under 3.0 g/dL) and high cholesterol with heavy protein define nephrotic syndrome.
  • Glucose and A1C — diabetes is the most common cause of persistent proteinuria; the A1C also tells you how much of it is modifiable.
  • Blood pressure — hypertension is both a cause and a consequence; the target in proteinuric kidney disease is generally under 130/80 mmHg.
  • Leukocytes and nitrite in urine — a urinary infection raises protein temporarily; retest after treatment before concluding anything.
  • Serum and urine protein electrophoresis with free light chains — ordered when proteinuria is heavy but the dipstick is weak, or in anyone over 50 with anemia, bone pain or unexplained kidney impairment, to look for myeloma.

What usually happens next

  1. A trace or 1+ result on a single sample is repeated on a first-morning midstream clean-catch sample when you are well, not after exercise, fever or dehydration; if it is negative, nothing further is usually needed.
  2. If protein persists, or the first result was 2+ or more, expect an albumin-creatinine or protein-creatinine ratio, serum creatinine and eGFR, blood glucose or A1C, a blood pressure check and a urine microscopy for blood and casts; the ratio is confirmed on two of three samples over 3 to 6 months.
  3. Under 30, with protein in daytime samples only, a first-morning sample that is negative confirms orthostatic proteinuria, which needs no treatment beyond an occasional check.
  4. A ratio above 300 mg/g albumin (or above about 0.5 to 1 g/g protein), any protein with blood and casts, a falling eGFR or nephrotic-range protein leads to nephrology referral, a kidney ultrasound and often a biopsy.
  5. In pregnancy, any new protein after 20 weeks prompts a blood pressure check, a protein-creatinine ratio and blood tests for platelets, liver enzymes and creatinine the same day.
  6. Ask: what is my albumin-creatinine ratio in mg/g, what is my eGFR, is my blood pressure at target, and should I be on an ACE inhibitor, ARB or SGLT2 inhibitor, the medicines shown to lower protein and protect the kidney?

Diet, lifestyle and natural levers with evidence

What can move Protein in urine once the cause is known. Nothing here replaces finding the cause.

Reduce sodium (salt) intake

Strong evidence

Salt raises glomerular pressure and blunts the protein-lowering effect of ACE inhibitors and ARBs. A 2021 Cochrane review of 21 randomised trials in chronic kidney disease found that cutting salt intake lowered blood pressure by about 7/4 mmHg and reduced albuminuria by roughly a third, with the effect seen within weeks. Most trials brought intake down to around 2 g of sodium (5 g of salt) a day, mainly by cutting processed foods, bread, deli meats and restaurant meals.

People with salt-losing kidney disease, those on high-dose diuretics and anyone advised to use salt substitutes should check first; potassium-based substitutes are unsafe with reduced kidney function or potassium-sparing drugs.

Tight blood glucose control in diabetes

Strong evidence

In the DCCT trial of 1,441 people with type 1 diabetes, intensive glucose control (mean A1C about 7 percent versus 9 percent) reduced the development of microalbuminuria by 39 percent and of albuminuria by 54 percent over 6.5 years, and the benefit persisted for decades afterwards. In type 2 diabetes, UKPDS showed a similar reduction in microalbuminuria with each 1 percent fall in A1C. Diet, activity and weight loss contribute, alongside medication.

Very tight targets increase hypoglycaemia; the A1C goal is individualised, and protein reduction in established diabetic kidney disease depends more on blood pressure drugs and SGLT2 inhibitors than on glucose alone.

Weight loss if overweight

Moderate evidence

Excess body weight makes the glomeruli hyperfilter. A systematic review of 31 studies found that weight loss, whether by diet, exercise or surgery, reduced proteinuria and albuminuria in proportion to the kilograms lost: roughly 110 mg per day less protein and 1.1 mg per day less albumin for each kilogram, independent of blood pressure changes. In the Look AHEAD trial, intensive lifestyle intervention in type 2 diabetes reduced the development of very high-risk kidney disease by about 30 percent over 8 years.

Very-low-protein crash diets and high-protein weight-loss diets can both be unwise with reduced kidney function; a dietitian familiar with kidney disease can help.

Moderate, not high, protein intake

Moderate evidence

High-protein diets (above about 1.3 g per kg of body weight a day) increase glomerular pressure and protein leak, while restricting intake to around 0.8 g/kg/day, the level recommended by KDIGO for people with chronic kidney disease not on dialysis, modestly reduces proteinuria and slows eGFR decline in randomised trials. Plant-based protein sources appear to produce less hyperfiltration than red meat in observational and short-term studies.

Protein restriction below 0.6 g/kg/day risks malnutrition and should only be done under dietetic supervision; it is not recommended in pregnancy, older frail adults or people with nephrotic syndrome who are losing large amounts of protein.

Stop smoking

Moderate evidence

Smoking roughly doubles the risk of developing albuminuria in people with diabetes and hypertension and accelerates loss of kidney function, through vascular damage and increased glomerular pressure. Cohort studies show albuminuria falls and kidney decline slows within a few years of stopping, and former smokers' risk approaches that of never-smokers over about a decade.

Regular physical activity

Moderate evidence

Despite the temporary protein rise straight after hard exercise, regular moderate activity lowers albuminuria over months. Meta-analyses of exercise trials in type 2 diabetes and chronic kidney disease report reductions in albumin-creatinine ratio of around 20 to 30 percent with 150 minutes a week of aerobic or combined training, with parallel improvements in blood pressure, weight and glucose.

Do not test urine protein within 24 hours of a hard session or a race; the transient rise can be mistaken for disease.

When to see a clinician promptly

  • Protein in urine during pregnancy after 20 weeks with a blood pressure of 140/90 mmHg or higher, severe headache, visual disturbance, pain under the right ribs, sudden swelling of the face or hands, or reduced baby movements: possible preeclampsia, go to your maternity unit the same day.
  • Protein with visible blood in the urine, cola-colored urine, or a recent sore throat or skin infection followed by swelling: possible glomerulonephritis, needs prompt assessment.
  • Sudden swelling of the legs, around the eyes or of the abdomen, frothy urine and weight gain over days: possible nephrotic syndrome.
  • Protein with reduced urine output, breathlessness, chest pain or confusion, which can indicate rapidly worsening kidney function or fluid overload: emergency care.
  • Persistent protein on two or more samples, 2+ or more on any sample, or an albumin-creatinine ratio above 30 mg/g, for a kidney function check and, if confirmed, a plan to lower it.
  • Protein in anyone with diabetes, high blood pressure, lupus, a family history of kidney disease or a single kidney, even if the amount seems small.

Frequently asked questions

What does protein in urine mean?

It means the kidney filters are letting through more protein, mainly albumin, than they should. On a single dipstick it is often temporary, caused by fever, exercise, dehydration, infection or standing for long periods, and goes away on repeat. When it persists, it usually points to kidney damage from diabetes or high blood pressure, or less often to glomerular disease, and it is the earliest and most important warning sign of kidney disease that can progress.

What is the normal range for protein in urine?

Negative on a dipstick, under 150 mg of protein in 24 hours, a protein-creatinine ratio under 0.15 to 0.2 g/g, and an albumin-creatinine ratio under 30 mg/g. Trace on a dipstick (about 15 to 30 mg/dL) is usually within normal, especially in concentrated urine. In pregnancy up to 300 mg a day is normal. Labs differ slightly in their cut-offs, so check the printed range on your report.

Is trace protein in urine something to worry about?

Usually not. Trace is the smallest detectable amount and is commonly caused by concentrated urine, exercise in the past day, fever, a cold, a urinary infection or standing for long periods. The usual advice is to repeat the test on a first-morning sample when you are well. If the repeat is negative, nothing more is needed. If trace persists, or you have diabetes or high blood pressure, an albumin-creatinine ratio measures it properly.

What does 1+, 2+ or 3+ protein in urine mean?

They are dipstick grades of roughly 30, 100 and 300 mg/dL. One plus is mildly positive and is often transient or orthostatic in young people, but is quantified if it persists. Two plus is significant and rarely explained by dilution alone; it needs a protein-creatinine ratio, creatinine and eGFR, blood pressure and glucose checks. Three plus or more is heavy proteinuria, often in the nephrotic range, and needs prompt assessment for glomerular disease, diabetic kidney disease or, in pregnancy, preeclampsia.

What does protein in urine mean during pregnancy?

A little protein (up to 300 mg a day) is normal in pregnancy because the kidneys filter more blood. Protein above that after 20 weeks together with a blood pressure of 140/90 mmHg or higher is preeclampsia, which is why urine and blood pressure are checked at every visit. A positive dipstick is confirmed with a protein-creatinine ratio (0.3 or above is significant). Protein found before 20 weeks suggests pre-existing kidney disease or a urinary infection rather than preeclampsia.

Can dehydration cause protein in urine?

It can make a dipstick read positive because the strip measures concentration, so the same small leak looks like trace or 1+ in concentrated urine and negative in dilute urine. Dehydration itself also briefly reduces kidney blood flow and raises protein a little. A ratio test corrects for concentration, and a repeat when well hydrated usually clears the result. Dehydration does not cause 2+ or more, which needs another explanation.

Can protein in urine go away or be reversed?

Transient and orthostatic proteinuria go away on their own. Early diabetic or hypertensive albuminuria (30 to 300 mg/g) often falls back toward normal with good blood pressure and glucose control, salt reduction, weight loss and medicines such as ACE inhibitors, ARBs and SGLT2 inhibitors, which lower protein by 30 to 40 percent. Heavier protein from glomerular disease depends on the cause; some conditions respond fully to treatment, others are controlled rather than removed.

Does protein in urine mean kidney failure?

No. Most people with protein in their urine have normal or near-normal kidney function, and the point of finding it is to protect that function. Protein is a marker of damage and a predictor of risk: the more protein, the faster kidney function tends to decline without treatment. Kidney failure is defined by the eGFR (below 15 mL/min/1.73 m²), not by protein. Someone with persistent proteinuria and a normal eGFR who treats the cause can keep normal kidney function for life.

References

  1. Protein in urine test. MedlinePlus, US National Library of Medicine (2023)View source
  2. Protein in urine (proteinuria). Mayo Clinic (2024)View source
  3. Proteinuria. Merck Manual Professional Version (2024)
  4. Carroll MF, Temte JL. Proteinuria in adults: a diagnostic approach. American Family Physician (2000)
  5. Kidney Disease: Improving Global Outcomes (KDIGO) CKD Work Group. KDIGO 2024 clinical practice guideline for the evaluation and management of chronic kidney disease. Kidney International (2024)
  6. Albuminuria. National Kidney Foundation (2024)View source
  7. Gestational hypertension and preeclampsia: ACOG Practice Bulletin No. 222. Obstetrics & Gynecology, American College of Obstetricians and Gynecologists (2020)
  8. McMahon EJ, Campbell KL, Bauer JD, Mudge DW, Kelly JT. Altered dietary salt intake for people with chronic kidney disease. Cochrane Database of Systematic Reviews (2021)
  9. Afshinnia F, Wilt TJ, Duval S, Esmaeili A, Ibrahim HN. Weight loss and proteinuria: systematic review of clinical trials and comparative cohorts. Nephrology Dialysis Transplantation (2010)
  10. Diabetes Control and Complications Trial Research Group. The effect of intensive treatment of diabetes on the development and progression of long-term complications in insulin-dependent diabetes mellitus. New England Journal of Medicine (1993)
  11. Simerville JA, Maxted WC, Pahira JJ. Urinalysis: a comprehensive review. American Family Physician (2005)
  12. American Diabetes Association Professional Practice Committee. Chronic kidney disease and risk management: Standards of Care in Diabetes 2024. Diabetes Care (2024)

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This page is educational and is not medical advice or a diagnosis. Lab results have to be interpreted together with your history, symptoms and other results by a clinician who knows you. Do not start or stop a supplement to change a lab value before the cause is known.