In this article, we look at types of urine tests for diabetes and how to understand the results.
What is a urine test for diabetes?
A urine test is when a urine sample is analysed. It may reveal a number of things, including the presence of glucose.
Urine tests are important for both the diagnosis and monitoring of diabetes. Urine testing is less accurate than blood testing but is useful as a screening test for people who already know they have diabetes.
Urine tests can also be used to check for glucose in the urine of people who are undiagnosed.
A urine test will be looking for three things: glucose, ketones, and protein.
Having glucose in the urine may indicate diabetes, although it can also be caused by other conditions. For example, pregnant women who do not have diabetes may have glucose in their urine.
Glucose is not normally found in urine, but it can pass from the kidneys into the urine in people who have diabetes.
Ketone is a chemical that the body produces when there is a shortage of insulin in the blood. It is a by-product produced when the body starts to break down body fat for energy.
The presence of ketones in a person with diabetes may indicate a high blood glucose level, usually because a person with diabetes cannot use glucose as energy and has to use fat instead. Ketones in the blood can then spill into the urine.
A doctor will check for the presence of protein in the urine of people with diabetes, as this can indicate kidney problems or a urinary tract infection.
Types of tests
A urine test may be referred to as a "dipstick test."
If someone is concerned that they may have diabetes, they should see a doctor as soon as possible. The doctor will ask about a person's symptoms and often take a blood and urine test.
The urine test used may be referred to as the "dipstick test" as it involves dipping a strip into the urine and reading the results using a color chart.
People who already have diabetes may be advised to test their urine for glucose or ketones at home. This urine test is very similar to the one used by doctors and can be purchased, without prescription, from a pharmacy.
During a urine test the doctor will give the person a clean and clear container and ask them to do the following:
- urinate a little first before filling the container, as a mid-stream specimen gives the most accurate reading
- fill three-quarters of the container and secure the lid
- give the sample back to the doctor or place it in a specified area
A doctor will dip a strip into the urine that will change color according to the levels of various substances in the urine. The doctor will measure the strip against a color chart to determine the level of glucose, ketones, and protein in the urine.
The procedure will be slightly different for a person already diagnosed with diabetes who is conducting a urine test at home.
A person doing a home test should do the test in the morning before eating breakfast. They should also empty their bladder immediately after getting up and test during the next time they pass urine.
The person will also be able to use a color strip and reference chart to check the levels of ketones, proteins, and glucose in their urine.
It is important to note that urine tests will not show if blood glucose levels are too low, which can be important for people on insulin or using specific medication.
A doctor may want to conduct a urine test if people with diabetes are experiencing any of the following symptoms:
- high blood glucose levels
- nausea, vomiting, or abdominal pain
- cold or flu symptoms
- persistent fatigue
- very thirsty or has a parched mouth
- flushed skin
- difficulty breathing or breath smells unusual
A strip will be dipped into the urine sample during the test. The different blocks of color change indicate levels of substances such as ketones or glucose.
The test results will identify the levels of glucose, ketones, and protein in the urine.
If a urine test finds glucose, then a specialized blood test, known as glycated hemoglobin (HbA1c), will be used to determine if a person has diabetes.
A glucose tolerance test (GTT) may also be carried out to see whether the body is having problems processing glucose.
High blood glucose is known as hyperglycemia and is common in people with all types of diabetes.
If a person has small traces of ketones in their urine, it may be a sign that ketones are building up and the person should take another test in a few hours.
If there are moderate or large amounts of ketones in the urine, then the person may have diabetic ketoacidosis (DKA), which is a potentially life-threatening complication of diabetes that requires urgent treatment.
Ketoacidosis is a chemical imbalance in the blood that can poison the body. It is a sign that a person's diabetes is out of control.
Some extremely low carbohydrate diets can cause the body to break down fat and produce ketones for fuel. A low carb diet alone does not cause ketoacidosis and is different to DKA. People with diabetes should discuss any diet changes with their doctor before beginning.
Protein in the urine can also be a sign of kidney disease (or diabetic nephropathy) and affects around 1 in 3 people with diabetes.
A person newly diagnosed with diabetes will start treatment immediately.
Children with type 1 diabetes and their parents or guardians will usually be introduced to a specialist diabetes care team who will teach them how to manage the child's condition.
Lifestyle changes, a healthful diet, and regular exercise can help a person with type 2 diabetes manage their symptoms. Medication will usually be prescribed to help lower blood glucose levels and keep it under control.
If a urine test has shown high blood glucose levels in someone who has diabetes, a doctor will advise them to:
- avoid food and drinks high in sugar or carbohydrates
- drink plenty of water
- exercise regularly
- possibly adjust insulin dose
People with diabetes who get a positive ketone test should contact their doctor immediately, as they may need more insulin. They should also drink plenty of water, not exercise, and keep testing for ketones every 3 to 4 hours.
Treatment for kidney disease will depend on its stage but can range from simple lifestyle changes to dialysis or a transplant.