A urine test is non-invasive, and people often use them at home. However, healthcare professionals may use a urine test if they cannot access a vein for a blood test, or if a person has anxiety or a fear of needles.
The results may be less accurate than those of a blood test, but urine tests can still play an important role.
In this article, we look at types of urine tests for diabetes and how to understand the results.
Types of test
A urine test can detect various substances, including glucose, ketones, protein, bacteria, and bilirubin.
A urine test is an noninvasive way of testing for glucose, ketones, and other substances.
Typically, glucose is not present in urine. However, when a person has diabetes, glucose can pass from the kidneys into the urine.
Other conditions, such as pregnancy and kidney disorders, can also lead to glucose in the urine.
Pregnancy: Around half of women have glucose in their urine during pregnancy, even if they do not have diabetes.
A person who has high levels of glucose in the urine during pregnancy may need monitoring for gestational diabetes.
This is a type of diabetes that occurs in some people during pregnancy. It usually resolves after delivery, but it can affect the fetus, lead to complications during labor, and may put the individual at a higher risk of developing type 2 diabetes later in life.
Glycosuria: This is a rare kidney condition in which a person does not have high blood glucose levels, but their kidneys excrete high levels of glucose into the urine. There are often no symptoms, but some people may experience thirst, urination, and other symptoms. In rare cases, dehydration or ketoacidosis can occur.
When a person has diabetes, the glucose in their blood cannot enter the body's cells, and it remains in the blood. When this happens, the cells do not have enough glucose for energy.
As a result, the body starts to break down fat to use for energy instead. This produces toxic ketones. If ketone levels rise too far, they can cause the blood to become too acidic. In a person with diabetes, this can lead to diabetic ketoacidosis (DKA), a potentially fatal condition that needs emergency treatment.
Ketones can also enter the urine, so a doctor can use a urine test to detect DKA. People with diabetes can do a urine test at home if they start to experience the signs and symptoms of DKA.
According to the American Diabetes Association, symptoms of DKA include:
- a "fruity" or acetone smell on the breath
- frequent urination
- dry or flushed skin
- difficulty breathing
- abdominal pain
- nausea and vomiting
- high blood sugar levels
- In severe cases, a person may experience:
- a loss of consciousness
- a coma
Anyone who thinks they might have DKA should first check their blood sugar levels. If these are over 240 milligrams per deciliter (mg/dl), the ADA recommend testing for ketones.
If ketone levels are high, seek medical help at once to prevent further problems developing.
DKA often takes time to develop, but if a person experiences vomiting, it can quickly become severe. It can affect people with both type 1 and type 2 diabetes.
The risk of DKA is also higher when a person with diabetes has a cold or flu. During these times, they should test their ketone levels every 4–6 hours, according to the ADA.
Knowing about self-testing for both glucose and ketones can enable a person with diabetes to have more control over their condition.
A doctor may test for protein in the urine to monitor for kidney problems. This is because diabetes increases the risk of chronic kidney disease (CKD) and specifically diabetic nephropathy. An early sign of diabetic nephropathy is protein in the urine.
If a person receives an early diagnosis of kidney disease, they may be better able to control it through diet and possibly medications.
Learn more here about diabetic kidney disease.
A doctor may use a urine test to check for a urinary tract infection (UTI).
People with diabetes have a higher risk of infections, including a UTI. Without treatment, this can lead to complications, such as a kidney infection.
The doctor will send the sample to a laboratory for culturing if a person has diabetes. If an infection is present, they may prescribe antibiotics.
Sometimes a urine test can detect bilirubin, a substance which can indicate liver damage and certain other health conditions.
What to expect
People sometimes call a urine test a dipstick test because it involves dipping a strip into the urine and reading the results using a color chart. Home tests are similar to these.
At the doctor's office
If the testing strip changes color, ketones, glucose, or other substance may be present.
At the doctor's office, a health professional will give the individual a clean, 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, which will change color according to the levels of various substances in the urine.
The doctor will compare the strip with a color chart to determine the level of glucose, ketones, and protein in the urine.
If the pH of the urine is high, this can indicate the presence of certain bacteria. However, the doctor may also need to send the sample to a laboratory for culturing if they are testing for a UTI. This can reveal the type of bacteria present and gives an idea of which treatment to prescribe.
The procedure is slightly different if a person already has a diagnosis of diabetes and is conducting a urine test at home.
At home, the person should follow the instructions on the testing kit, as these can vary. However, it will likely involve a color strip and a reference chart for checking the levels of ketones, proteins, or glucose in the urine.
They should do the test in the morning before eating breakfast.
It is important to note that urine tests will not indicate whether blood glucose levels are too low. This may be important for people who are at risk of hypoglycemia (low blood glucose). Those who use insulin or other medications may need to monitor for low blood sugar.
The test results will identify the levels of glucose, ketones, and protein in the urine.
The doctor may suggest adjusting treatment, depending on the results.
If a urine test identifies glucose, a doctor will usually carry out an or A1C, or glycated hemoglobin (HbA1c) blood test to determine if a person has diabetes.
They may also do a glucose tolerance test (GTT) to find out if the body is having problems processing glucose.
If a person has high levels of glucose in their urine, this may be due to diabetes. If so, they will also have high levels of glucose in their blood (hyperglycemia).
In the short-term, uncontrolled high blood sugar levels can lead to symptoms such as thirst, a need to urinate often, and an increased risk of DKA. In the long-term, it can lead to widespread damage throughout the body and a wide range of conditions, such as cardiovascular disease.
Knowing as soon as possible whether their blood sugar levels are high means a person can take measures to prevent the condition from worsening.
If a person has a diagnosis of type 1 diabetes, they will need insulin to control blood sugar levels. Type 1 diabetes usually develops during childhood or young adulthood, but it can occur at any time. It can also appear quickly, over some weeks.
Type 2 diabetes usually appears later in life and takes years to develop. A diagnosis of prediabetes will enable a person to make lifestyle changes that can slow or reverse the progress of the condition.
A person with diabetes who finds ketones in their urine needs to seek medical advice to prevent the problem from getting worse.
If ketone levels are high, they may need treatment in the hospital, with:
- intravenous insulin
- intravenous fluids and electrolytes
Some low-carb 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 from DKA.
However, a person with diabetes should discuss their dietary plan with their doctor and seek advice on any nutritional changes they wish to make.
Protein in the urine can be a sign of kidney disease.
A person with diabetes should speak to their doctor if they notice the following symptoms:
- swelling due to fluid retention
- sleep problems
- low appetite
- difficulty focusing
People with kidney disease often do not notice any symptoms until the later stages, when the kidneys no longer work effectively. This can lead to severe complications.
A doctor may offer regular screening for protein in the urine, as this can help detect kidney problems in the early stages, while there is still time to take preventive action.
People may have a higher risk of kidney disease if they have:
- certain genetic factors
- persistent high blood sugar
- high blood pressure
Addressing high glucose and blood pressure can reduce the risk.
If a person finds ketones in their urine, they should ask their doctor for advice. If a doctor finds high levels of glucose, ketones, or protein in a person's urine, they may order further tests.
Depending on the results, they will advise on the next steps.
If urine or other tests reveal high levels of protein, glucose, or ketones, the person should take measures to prevent any problems from getting worse.
Often, lifestyle measures — such as a healthful diet and exercise — are key to reducing the risks of further complications. However, a doctor may also prescribe medication or recommend hospitalization in some cases.
I would like to to do my testing at home before going to the doctor for confirmation. Can I get home tests for all of the above, or only for ketones? How reliable are home testing kits?
Yes, you can test for several things, including glucose, ketones, bilirubin, and more at home. To ensure reliability, check that the test strips have not expired and follow the directions carefully.
In most cases, it is necessary to compare the color of the strip against a color chart. You will need to do this a specific amount of time after dipping the strip in the urine.
Be prepared with good lighting and a timer to help you accurately read the results.Deborah Weatherspoon, PhD, RN, CRNA Answers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.