Examining urine to help diagnose diseases is called urinalysis. There are different stages of urinalysis.
Physical examination
Your doctor or nurse can examine your child’s urine for clues about their health, by looking at:
- its colour
- its smell
- its cloudiness
Dipstick test
Your doctor or nurse will place a dipstick into the urine. The dipstick is a strip with chemical pads that change colour depending on what substances are in the urine.
The dipstick can detect signs of a urinary tract infection (UTI), protein, blood, sugars, and acid (pH balance).
Dipstick and laboratory tests explained
Dipstick test
Infection
If there are certain substances in your child’s urine, this may be a sign there is a urinary tract infection (UTI). UTIs are caused by germs – these are usually bacteria – that affect one or more parts of the urinary system.
White blood cells are a type of cell normally found in the blood that helps the body fight infection.
Nitrites are chemicals that the body sometimes makes when there is a bacterial infection.
Protein
The dipstick can show whether there is protein in your child’s urine. There is usually no or very little protein in the urine – an abnormal amount is called proteinuria.
If your child’s urine sample shows proteinuria, your doctor will do more tests to find out more.
Blood
The dipstick can show whether there is blood in your child’s urine – this is called haematuria. There is usually no blood in the urine.
If your child’s urine sample shows haematuria, your doctor will do more tests. If there is a lot of blood, the urine may be coloured red or dark brown (like a cola drink).
Sugars and other substances
Glucose is a type of sugar, and may be found in the urine in some conditions such as diabetes. If there are substances called ketones in your child’s urine, this may be a sign of dehydration (not enough water in the body).
Concentration
A specific gravity test finds out how concentrated the urine is. This can give your doctor information about how well your child’s kidneys are working (kidney function).
Laboratory test
Infection
Urine cultures check whether the urine sample has germs, such as bacteria and yeasts (a type of fungus). It can take up to 48 hours for this result to be available.
Protein
The dipstick urine test can detect whether there is any protein, but is not very accurate. Your doctor may also calculate the amount of protein. He or she can do this by comparing the amounts of protein and creatinine in the urine. Creatinine is continuously made by muscles and normally removed by the kidneys in urine.
There are two measurements that can be used.
- Urine protein:creatinine ratio (PCR) – this measures the amount of all protein and the amount of creatinine. The ratio compares the amount of protein to the amount of creatinine.
- Albumin:creatinine ratio (ACR) – this measures the amount of one type of protein called albumin and the amount of creatinine in the urine. The ratio compares the amount of albumin to the amount of creatinine.
If your child needs to have this test, he or she will normally need to provide a sample of their first morning urine, the urine that they pass when they first wake up in the morning and go to the toilet.
Blood
The dipstick urine test can detect whether there is any blood. A laboratory test can identify and count the number of blood cells.
Laboratory test
Depending on the results of the dipstick test, the sample may be sent to a laboratory to be looked at under a microscope. These tests will help with the following:
- to confirm whether there is an infection, and which germs are causing it
- if there is protein in the urine, to find out how much is there
- if there is blood in the urine, to count the number and types of blood cells
- how concentrated the urine is – to give more information about how well the kidneys are working (kidney function).