Urinalysis

A urinalysis is a group of tests done to examine your urine (pee). It finds and measures substances such as electrolytes, sugar (glucose), proteins, blood, cells and bacteria. It may also be called a urine test.

A urinalysis is often done as part of a routine checkup, but it can be done at any time. It may be done to:

• learn about your general health
• check how well organs of the urinary system are working
• check for kidney problems, kidney disease, urinary tract infections or diabetes
• check if a woman is pregnant
• help diagnose certain cancers, such as kidney cancer and bladder cancer
• monitor a condition (as a part of follow-up)

A urinalysis is usually done in a community lab or hospital.

You don’t usually need any special preparation for a urinalysis. But in some cases, you may be given special instructions to follow before having a urinalysis done. You could be asked to stop taking certain medicines, not eat or drink anything for several hours (called fasting) or avoid certain foods.

Your urine is collected in a clean container. A random urine sample is most commonly collected for a urinalysis. This means a small amount of urine is provided at any time of day. But you may be asked to collect the urine at a specific time of day, such as first thing in the morning.

The lab will give you instructions on how to collect the urine and how much of it to keep. Before you collect the urine sample, you will clean your genital area (between the labia in women or the tip of the penis in men). Start to urinate in the toilet (you don’t collect the first bit of urine). Then collect some urine in the container (called midstream urine or clean-catch).

Sometimes a 24-hour urine sample is needed to help doctors better understand what is happening in the body. This means you collect all your urine over a period of 24 hours. The urine is put into a large container, which sometimes contains special preservatives or needs to be kept cold. The lab will give you with instructions to follow for collecting the 24-hour urine sample.

The urine sample is then examined by a specialist at the lab (a lab technologist). Special paper strips (called dipsticks) and a microscope are used to examine the urine.

A urinalysis provides general information that can give doctors clues to possible health problems. Information from a urinalysis helps doctors decide if other tests or procedures are needed to make a diagnosis. The information may also help your doctor develop or revise treatment plans.

Urinalysis results should be compared to a normal reference range to have meaning. A doctor familiar with your medical history and overall health is the best person to explain your urinalysis results and what they mean for you.

A urinalysis and its results are usually divided into 3 parts:

• what the urine looks like (visual exam)
• levels of certain chemicals or substances (chemical exam)
• cells and bacteria in the sample (microscopic exam)

The following are some examples of urinalysis results and what they may mean.

Normal urine is pale to dark yellow and clear. An abnormal colour in the urine can be caused by certain medicines or foods. Cloudy urine can mean that blood cells or bacteria are in the sample.

Urine is usually slightly acidic. Having urine that is very acid or very alkaline may mean you at increased risk of developing kidney stones (hard deposits of minerals such as calcium that start forming in the kidney).

Certain substances are not usually found in urine.

• Protein in the urine (proteinuria) may mean kidney problems, kidney disease, high blood pressure, inflammation of the urinary tract or cancer in the urinary tract.
• Sugar in the urine may mean diabetes or disease of the liver or pancreas.
• Blood in the urine (hematuria) may mean there is bleeding in the urinary tract, which could be caused by cancer.
• Bilirubin in the urine may mean there is cancer in the liver or a bile duct is blocked by a tumour.

Looking at urine through a microscope can find cells, parts of cells and bacteria or other germs.

• An increased number of red blood cells (RBCs) and hemoglobin in the urine means there is blood in the urine.
• An increased number of white blood cells (WBCs) in the urine may mean there is an infection or inflammation in the urinary tract.
• An increased number of epithelial cells in the urine may mean there is an infection, inflammation or cancer.
• Bacteria in the urine may mean there is an infection in the urinary tract or vagina.

If abnormal results are found, your doctor may have you give another sample for urinalysis. Your doctor may recommend other tests, procedures, follow-up care or treatment.

It can be more difficult to get a urine sample from a child. For children who are not toilet-trained, a tube ( catheter) may be inserted into the urethra to collect urine into a plastic bag that is connected to the tube. For babies, a special bag can be used instead of a diaper to collect urine.

Preparing a child for a urinalysis depends on the age and experience of the child. Find out more about helping your child cope with tests and treatments.