Protein in urine: normal range and what a positive result means

Protein in urine, or proteinuria, means the urine is carrying more protein than the small amount healthy kidneys let through. A urine test picks it up on a strip pad and reports it as negative, trace, or one to four plus signs. A single positive result is common and often temporary. Protein that keeps showing up is one of the earliest signs that the kidneys' filters are under strain, which is why it is worth understanding rather than ignoring.

What it measures

Each kidney filters blood through tiny units called glomeruli. Their walls let water, salts and small molecules through but hold back most proteins, and the small proteins that do pass are taken back up further along the tubule. Healthy urine still contains a little protein: some albumin, some other blood proteins and some made by the urinary tract itself.

The strip pad is most sensitive to albumin, the main protein in blood. It can miss small amounts of albumin, and it can miss other proteins entirely, such as the light chains (Bence Jones protein) made in some blood disorders. When a doctor wants a precise number, they use a laboratory ratio instead.

Normal range

On a urine strip, the normal result is negative. As a rough guide, the strip readings correspond to these concentrations:

Where a lab reports a concentration, MedlinePlus gives 0 to 14 mg/dL as a common normal value for a random sample, and 30 to 150 mg over 24 hours for a full-day collection. A strip reading depends on how concentrated the urine is, so the more precise test is a ratio against creatinine measured in the same sample. KDIGO, the international kidney guideline group, grades the urine albumin-to-creatinine ratio (UACR) like this:

UACR is a separate test from the urine strip. Ranges vary by laboratory, method, age and sex, and the range printed on your report is the one to read against.

What a positive result usually points to

Short-lived causes

Many positive strips are temporary. Hard exercise, fever, dehydration, emotional stress and a urinary infection can all raise urine protein for a short time. So can long periods on your feet: in orthostatic proteinuria, protein appears in urine collected during the day but not in a sample taken after eight hours lying down, a pattern considered benign.

Protein that persists

When protein shows on repeat samples, the usual source is the glomerular filter, and albumin is the main protein lost. Diabetes and high blood pressure are the two conditions guidelines most often test for when protein appears. Inflammatory kidney conditions, some medicines (including long-term use of anti-inflammatory painkillers), heart failure and, less often, blood disorders such as multiple myeloma are other causes. MedlinePlus notes that the amount of protein tends to track how much the kidneys are affected.

What a doctor typically checks next

• A repeat test, often on an early morning sample, to see whether the protein persists.
• A urine albumin-to-creatinine ratio, or protein-to-creatinine ratio, to put a number on it.
• Kidney function in blood: creatinine and eGFR.
• Blood pressure, HbA1c and fasting glucose.
• The rest of the urine test: red cells or red cell casts alongside protein point towards the kidney's filters.

What moves it

• Exercise. Strenuous exercise in the day before raises urine protein and albumin.
• Concentration. A concentrated sample reads higher on the strip and a dilute one lower, which is one reason ratios are used.
• Infection, fever and menstruation. All can add protein; blood in the sample raises it.
• Diet. Laboratory guidance suggests avoiding a high-protein diet in the day before a urine test.
• Pregnancy. Protein in urine is checked in pregnancy alongside blood pressure, because together they are part of how pre-eclampsia is assessed. NICE advises measuring a ratio when a strip reads 1+ or more.
• Alkaline urine and containers. Very alkaline urine (around pH 9), a strip left in the sample too long, or some cleaning agents left in a container can give a false positive.
• Scans and medicines. Contrast dye from a scan in the 3 days before can affect the result, as can a number of medicines.

Preparing for the test

No fasting is needed for urine protein. An early morning, midstream sample is preferred for albumin testing. Avoid hard exercise for about a day beforehand. If you have your period, say so, since blood in the sample raises protein. Mention any recent scan with contrast dye and the medicines you take.

How Clare's panel handles it

In Clare's panel, urine protein is measured by the lab, from the same urine sample as the other 20 urine markers. The panel also measures creatinine and urea in blood and calculates eGFR from creatinine, so a positive urine result can be read against kidney function rather than on its own.

Why it matters in the UAE

Diabetes is the main reason urine protein gets attention here. The International Diabetes Federation estimates that 20.7% of adults aged 20 to 79 in the UAE had diabetes in 2024 (age-standardised). In a 2003 to 2004 survey of 513 people with diabetes in Al Ain, 12.5% had protein on a urine strip, and a more sensitive albumin strip was positive in 61%. A 2020 study of 207 UAE nationals with type 2 diabetes at a hospital clinic found moderately increased albumin in 44%. Both studies used one sample per person, and guidelines ask for a repeat before calling albuminuria persistent, so these figures show how often the question comes up rather than how often kidney disease is confirmed.

Ramadan fasting is the other local factor. A small UAE study of 31 people with chronic kidney disease, summarised in the IDF and DAR Ramadan guidelines, found no significant change in urine protein during and after the fast.

Related tests

Urine protein is read with creatinine and eGFR from the kidney function test, with urine blood (haemoglobin) and red cells from the rest of the urine test, and with HbA1c when diabetes is part of the picture. For how these fit into a wider panel, see our guide to a comprehensive blood test in Dubai.

Why it means more over time

Because so many positive strips are temporary, the second result is often more useful than the one before it. Guidelines ask for a raised UACR to be confirmed on an early morning sample, and they describe chronic kidney disease in terms of changes lasting at least three months. For people with diabetes or high blood pressure, urine albumin and eGFR are usually rechecked regularly, at a frequency agreed with their doctor, and a ratio that climbs across successive tests says more than any single value. A result that returns to negative on a later sample usually fits one of the temporary causes above.

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