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.
Type 2 diabetes occurs when cells are no longer able to use insulin effectively. This state is called insulin resistance. Type 2 diabetes develops gradually and is associated with being overweight and having a sedentary lifestyle.
Diabetes causes blood glucose, or 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. However, they may be used to monitor a person’s levels of urine ketones and urine glucose. Sometimes they’re used to ensure diabetes is being managed properly.
A urine test may be given as part of a routine checkup. A lab may test your urine for the presence of glucose and ketones. If either are present in the urine, it could mean that you’re not producing enough insulin.
Some diabetes medications such as canagliflozin (Invokana) and empagliflozin (Jardiance) cause an increase of sugar to spill into urine. For people taking these medications, glucose levels shouldn’t be tested by urine but testing ketones is still okay.
In the past, urine tests for glucose were used to diagnose and monitor diabetes. Now, they aren’t as commonly used anymore.
In order to diagnose diabetes more accurately, a doctor will typically rely on a blood glucose test. Blood tests are more accurate and can measure the exact amount of glucose in the blood.
Urine ketone testing is most often necessary in people with type 1 diabetes who:
- have blood sugar levels over 300 milligrams per deciliter (mg/dL)
- are sick
- have symptoms of diabetic ketoacidosis (DKA), an acute complication of diabetes
Ketone levels can be monitored with an at-home urine test kit. A urine test for ketones should be used if you match the descriptions above or have any of the following symptoms of DKA:
- vomiting or feeling nauseous
- persistently high sugar levels that don’t respond to treatment
- feeling sick, such as with the flu or an infection
- feeling exhausted or tired all the time
- excessive thirst or having a very dry mouth
- frequent urination
- breath that smells “fruity”
- confusion or feeling like you’re in a “fog”
You may also need to take a urine ketone test if:
- you’re pregnant and have gestational diabetes
- you’re planning to exercise and your blood glucose level is high
Shop for an at-home ketone test.
People with diabetes, especially type 1 diabetes, should get recommendations from their doctor as to when they should test for ketones. Typically, if your diabetes is well-managed, you may not be required to regularly check your ketone levels.
If you begin experiencing any symptoms as mentioned above, your sugar levels are above 250 mg/dL, or your body isn’t responding to insulin injections, then you may need to begin monitoring your ketone levels.
Before your 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’re 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.
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’re done. In general, this is what can be expected during an office urine test:
- You’ll be given a plastic cup labeled with your name and other medical information.
- You’ll take the cup into a private bathroom and urinate into the cup. Use the “clean catch” method to avoid contamination with bacteria or cells on your skin. With this method, you’ll only collect your urine midstream. The rest of your urine flow 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, or online. 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 involves the following steps:
- Start by reading the manufacturer’s instructions.
- 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 for the amount of ketones found in your urine.
- Immediately write down your results.
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 doesn’t test your current blood levels of glucose. It can only provide insights into whether or not glucose is spilling into your urine. It also merely reflects the state of your blood sugar over the prior few hours.
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’re 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 millimoles per liter (mmol/L), according to the National Health Service (NHS).
An abnormal result means you have ketones in your urine. The readings are usually classified as small, moderate, or large.
Small to moderate
A ketone level of 0.6 to 1.5 mmol/L (10 to 30 mg/dL) is considered small to moderate. This result may mean that ketone buildup is starting. You should test again in a few hours.
This time, drink plenty of water prior to the test. Don’t exercise if your blood glucose levels are also high. Starvation may also cause a small amount of ketones in the urine, so avoid skipping meals.
Moderate to large
A ketone level of 1.6 to 3.0 mmol/L (30 to 50 mg/dL) is considered moderate to large. This result can signal that your diabetes isn’t being managed well.
At this point, you should call your doctor or seek medical attention.
A ketone level greater than 3.0 mmol/L (50 mg/dL) can indicate that you have DKA. This is a life-threatening condition and requires immediate medical treatment. Go directly to the emergency room if your levels are this large.
Other than large ketone levels in the urine, the symptoms of ketoacidosis include:
- a breath odor described as “fruity”
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. You can manage your blood sugar levels with the help of:
If you have type 1 diabetes, you may have to regularly monitor ketone levels in your urine using a home test strip. If ketone levels get too large, you can develop DKA.
If the test shows that you have small or moderate ketones, follow the plan that you’ve set up with your healthcare team. If you have large levels of ketones in your urine, contact your healthcare provider right away or go to the emergency room.
DKA will be treated with intravenous (IV) 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 large ketones can help you and your doctor adjust your diabetes treatment plan.