Protein or blood in the urine is a clue worth following.
A urine test that shows protein or blood is common, and it does not always mean something serious. It can be brief, after a fever, hard exercise or a period. But when it stays, it can be the first sign of kidney damage, or, for blood, of a stone or a growth. A repeat test and a few simple checks usually show which.
In plain words.
Protein. Healthy kidneys keep almost all protein in the blood. A little can show for a short while with a fever, hard exercise or a urine infection. When it stays, the commonest causes are diabetes and high BP; others are inflammation of the kidney filters and some less common illnesses. The more protein leaks, the faster the kidneys tend to lose function, and lowering it with treatment protects them.
The best measure is the urine albumin-to-creatinine ratio (ACR) on an early-morning sample. A single raised result is repeated: protein that shows on two out of three tests over about three months is real.
Blood. It may colour the urine pink, red or cola-brown, or show only on a test. It can come from the kidney filters (often with protein and a cola colour), a stone, a urine infection, an enlarged prostate, or a growth in the kidney or bladder, which becomes more likely after 40 and in smokers. A period can get into the sample, so women repeat the test once it is over.
Visible blood in the urine, even once and even without pain, always needs to be checked, especially after the age of 40. Red urine is not always blood: beetroot and some medicines, such as the TB medicine rifampicin, can colour it too, and the test tells them apart.
A sieve that starts to leak
The kidney filter is a very fine sieve. Water and waste pass through into the urine; protein and red cells are too big, and stay in the blood.
When the filter is damaged, by diabetes, high BP or inflammation, its gaps widen and protein slips through. The urine may look frothy, but often the leak only shows on a test.
An inflamed filter lets red cells through as well, often with some protein, and the urine may turn pink, red or cola-coloured. Blood can also come from lower down, from a stone, an infection or a growth, so it always needs checking.
Go to hospital now if
- Passing very little or no urine: go to hospital now.
- Unable to pass urine, or urine full of blood and clots: go to hospital now.
- Blood in the urine with feeling faint, dizzy or very weak: go to hospital now.
- Severe pain in the side with fever, shivering or vomiting: go to hospital now.
- Sudden swelling of the face and body with breathlessness: go to hospital now; call 112 if the breathing is bad.
Call 112 or go to the nearest emergency department. Ambulance: 108 (102 in some states).
See a doctor within a few days if
- You see blood in the urine, even once, and even if it has stopped
- Your urine stays frothy, and your eyes or feet start to swell
- You have blood in the urine with a fever or burning
- A report shows protein or blood, and your creatinine is raised or rising
Tests that help.
Not everyone needs every test. He decides which ones are worth doing for you.
| Test | What it tells |
|---|---|
| Repeat urine routine and microscopy | Confirms the finding. The shape of the red cells, and casts, can point to the kidney filters. |
| Urine albumin-to-creatinine ratio (ACR) | Measures the protein leak on one morning sample; used to follow it over time. |
| Urine culture | Looks for an infection, which can cause both protein and blood for a while. |
| Creatinine and eGFR | How well the kidneys are filtering. |
| Ultrasound of the kidneys and bladder | Looks for stones, blockage, growths and the size of the kidneys. |
| HbA1c and BP readings | Diabetes and high BP are the commonest causes of protein in the urine. |
| CT scan and cystoscopy | For visible blood, or blood after 40: a scan and a camera look into the bladder, with a urologist. |
Have it ready.
Tick them off as you gather them. The ticks stay on this phone only.
Online, or in person?
Blood thinners such as aspirin, clopidogrel or warfarin make bleeding more likely, but blood in the urine on a blood thinner still needs checking, because there may be another cause. Do not stop a blood thinner on your own: ask first.
A video call can
Needs a visit in person
- The urine sample, blood tests and ultrasound
- Cystoscopy and CT scan with a urologist
- A kidney biopsy, when a kidney specialist needs one
- Any sign in the red box: that is an emergency
Talk it through with Dr. Arya.
Bring your reports and medicines to a video consultation. He goes through them with you, in plain words, and says clearly if you need to be seen in person.
Book a video consultationDr. Prabhat Arya · MBBS, MD (Internal Medicine) · Delhi Medical Council Reg. No. DMC-83759