Diseases

While urine tests can show signs that may signal diabetes, such as elevated sugar or ketones, the diagnosis of diabetes is made on the basis of blood tests. Urine tests may be done in some cases as back-up testing or for screening to see if blood tests should be done, but the diagnosis of diabetes is made after blood glucose testing.

Urine tests are tests performed in a clinical laboratory or at home using self-test kits and a sample of the patient's urine. Urine tests can be performed for a variety of reasons, but in people with diabetes, they are most commonly used to look for ketones or microalbumin (see below). Urine glucose (sugar) can also be measured, but this is less valuable than blood glucose levels for diagnosis and monitoring of diabetes, so this is not commonly done as a way to monitor blood glucose status.

The ketone test is generally recommended for people with type 1 diabetes. Those with type 1 diabetes should test their urine for ketones when they are ill, especially if they have vomiting and nausea. Pregnant women with type 1 diabetes may also be advised to test their urine for ketones. Ketone testing is also done when the blood sugar is noted to be very high (over about 240 mg/dL). Your doctor can advise you specifically about recommended testing practices for your individual situation. Sometimes, people with type 2 diabetes may be advised to check their urine for ketones. Those with type 2 diabetes should discuss with their doctor whether ketone testing is necessary and under what circumstances. The microalbumin test is done once per year starting at the time of diagnosis in people with type 2 diabetes. Even though protein in the urine is a sign of long-term damage to the kidneys, many people have type 2 diabetes without knowing it, so it is unclear how long they have had the condition. In people with type 1 diabetes, the micoalbumin test may not be performed until the condition has been present for up to 5 years.