What Are Urine Tests for Diabetes?
Diabetes is a condition that is characterized by high blood sugar levels. This is due to the body’s inability to make any or enough insulin, use insulin effectively, or both. Insulin is a hormone that helps the cells of your body absorb blood sugar to make energy. Insulin is produced by the pancreas after you eat food. There are two major classifications of diabetes:
- Type 1 diabetes occurs when the body’s immune system attacks and destroys insulin-producing cells in the pancreas. This type is usually diagnosed in childhood and develops quickly. Symptoms include quick weight loss, excessive thirst, excessive urination, and fatigue. Type 1 makes up just 5 percent of diabetes cases in the United States.
- Type 2 diabetes is when cells aren’t able to use insulin effectively anymore. This is called insulin resistance. If the cells can’t take in and store glucose, the glucose remains in the blood. Eventually the pancreas is unable to produce enough insulin to keep blood sugar levels within normal ranges, and diabetes develops. This type of diabetes develops gradually and is associated with being overweight and having a sedentary lifestyle.
Diabetes causes blood glucose (blood sugar) to rise to abnormally high levels. In type 1 diabetes, the body may also begin to burn fat for energy because the cells aren’t getting the glucose they need. When this happens, the body produces chemicals called ketones. When ketones build up in the blood, they make the blood more acidic. A buildup of ketones can poison the body and result in coma or even death.
Urine tests aren’t ever used to diagnose diabetes, but they may be used to monitor a person’s levels of urine ketones and urine glucose and sometimes to make sure their diabetes is being managed well.
Who Should Have a Urine Test for Diabetes?
A urine test may be given as part of a routine checkup. A laboratory may test your urine for the presence of glucose and ketones in the urine. If either are present in the urine, it could mean that you are not producing enough insulin. Urine ketone testing is most often necessary in people with type 1 diabetes who have blood sugar levels over 300 mg/dl, who are sick, or who have symptoms of diabetic ketoacidosis, an acute complication of diabetes.
Urine tests for glucose were used in the past to test for and monitor diabetes, but they aren’t as commonly used anymore. In order to diagnose diabetes more accurately, a doctor will typically rely on a blood test. Blood tests are more accurate and can measure the exact amount of glucose in the blood.
People with type 1 diabetes should monitor their ketone levels. This can be done with an at-home urine test kit. A urine test for ketones should be used if:
- your blood glucose is more than 300 mg/dl
- you are vomiting or feel nauseous
- you are sick (such as with the flu)
- you feel exhausted or tired all the time
- you are thirsty or have a very dry mouth
- your breath smells "fruity"
- you are confused or you feel like you are in a “fog”
- you are pregnant and have gestational diabetes
- you are planning to exercise and your blood glucose level is high
How to Prepare for a Urine Test
Make sure to drink enough water so you can provide an adequate sample of urine. Be sure to tell your doctor about any medications or supplements you are taking, as these may affect the results.
Urine can easily be contaminated by bacteria and cells. You should cleanse your genital area with water before providing a sample of urine.
What to Expect During a Urine Test
You may be asked to give a sample of urine while at the doctor’s office. Urine test kits are also available for use at home. A urine test is fairly simple, and carries no risk. You shouldn’t feel any discomfort during this test.
At the Doctor’s Office
Your doctor will provide instructions on how to give the sample and where to leave it when you are done. In general:
- You’ll be given a plastic cup labeled with your name and other information.
- You’ll take the cup into a private bathroom.
- You will urinate into the cup. To avoid contamination with bacteria or cells on your skin, you should only collect the middle part of the urine that comes out (midstream, also called a “clean catch”). The first and last part of the urine can go into the toilet.
- Place the lid on the cup and wash your hands.
- Bring the cup to wherever your doctor told you to leave it when you’re done. If you aren’t sure, ask a nurse or other staff member.
- The sample will then be analyzed for the presence of glucose and ketones. The results should be ready shortly after the sample is given.
At-Home Test Strips
Ketone tests are available at the pharmacy without a prescription. Be sure to read the directions on the package carefully or go over how to use the strips with your doctor prior to doing the test. Before using the test strip, check to make sure it isn’t outdated or expired. In general, the at-home urine test is done the following way:
- Urinate into a clean container.
- Dip the strip in the urine. The strips are coated with chemicals that react with ketones.
- Shake the excess urine off the strip.
- Wait for the strip pad to change color. The instructions that came with the strips should tell you how long to wait. You may want to have a watch or timer available.
- Compare the strip color to the color chart on the packaging. This gives you a range of the amount of ketones in your urine.
- Immediately write down your results.
Understanding the Results of a Urine Test for Diabetes
Healthy individuals generally shouldn’t have glucose in their urine at all. If the test shows the presence of glucose in your urine, you should discuss the possible causes with your doctor.
Urine testing does not test your current blood levels of glucose. It can only provide insights into whether or not glucose is spilling into your urine. Blood glucose testing is the primary test used to determine actual glucose levels.
Monitoring ketone levels in urine is important if you have type 1 diabetes. Ketones are more commonly seen in the urine of people with type 1 diabetes than in people with type 2 diabetes. If you are told to monitor your ketones, ask your healthcare team to help you develop a plan for what to do if you do detect ketones in your urine.
Normal or trace levels of ketones in urine are less than 0.6 mmol/L, according to the University of Denver. An abnormal result means you have ketones in your urine. The readings are usually listed as small, moderate, or large:
- Small to moderate (0.6 to 1.5 mmol/L or about 10 to 30 mg/dL) may mean that ketone buildup is starting. You should test again in a few hours. Drink plenty of water during this time. Do not exercise if your blood glucose levels are also high.
- Moderate to large amounts (1.6 to 3.0 mmol/L or about 30 to 50 mg/dL) in the urine can be a signal that your diabetes is not being managed well. You should call your doctor or seek medical attention at this point.
- Very large amounts of ketones (greater than 3.0 mmol/L or more than 50 mg/dL) can indicate that you have a condition called ketoacidosis. This is a life-threatening condition and requires immediate medical treatment. Go directly to the emergency room if your levels are this high. Other than high ketone levels in the urine, the symptoms of ketoacidosis include vomiting, nausea, confusion, and a breath odor described as “fruity.” Ketoacidosis can cause brain swelling, coma, and even death If not treated.
Follow-Up After the Test
If glucose or ketones are found in the urine during a routine exam, your doctor will do additional testing to determine why this is happening. This may include a blood glucose test.
Your doctor will go over your treatment plan with you if you have diabetes. Diet management, exercise, medications, and testing your blood glucose levels can help you manage your blood sugar levels.
If you have type 1 diabetes, you may have to regularly monitor ketones levels in your urine using a home test strip. If ketone levels get too high, you can develop a serious complication called diabetic ketoacidosis (DKA). Check your ketone levels using a urine test if you have the following symptoms:
- are sick or have an infection
- excessive thirst
- dry mouth
- frequent urination
- high blood sugar (over 300 mg/dL)
- constantly feeling tired
- blushed skin
- nausea or vomiting
- sweet odor on breath that may be described as “fruity”
If the test shows that you have low or moderate ketones, follow the plan that you have set with your healthcare team. If you have high levels of ketones in your urine, contact your healthcare provider right away or go to the emergency room. The treatment of ketoacidosis is with intravenous fluids and insulin.
Speak with your doctor about what can be done to prevent future episodes. Keeping track of your results and the conditions that triggered an episode of high ketones can help you and your doctor adjust your diabetes treatment plan.