Urine Tests

While blood glucose testing is the primary way to test for high glucose, urine testing can also be useful: because excess glucose in the body eventually passes through urine, testing urine can provide insight into whether or not there is excess glucose throughout the rest of your body. Urine testing is also an important part of testing for ketones, which are dangerous by-products of diabetes that’s out of control.

Glucose Testing

Testing for glucose (blood sugar) in your urine is a way to tell how your body is treating excess glucose. Generally, the human body doesn’t “spill” glucose into urine unless levels become very high in your bloodstream. High levels of sugar in your urine can signal that something is wrong in the way your body treats glucose.

However, urine testing does not test your current levels of glucose—it only provides insight into what has occurred since the last time you used the restroom. This is why blood glucose testing is the primary test for actual glucose levels—it’s more accurate and gives you an instant snapshot of what’s occurring right then and there in your bloodstream.  

Ketones in Urine

The body produces ketones when it starts to use fat instead of carbohydrates (i.e. glucose) for fuel. When things are going right insulin helps our cells absorb the glucose that circulates in our bloodstream to use as fuel so we can breath, think, move, and function. When cells are not absorbing glucose, glucose builds up in the bloodstream and the body becomes desperate for fuel. Naturally, the body turns to fat for fuel and it starts to cannibalize its own tissue.

During stressful conditions, there may be a small amount of ketones in your urine. Often this occurs if you are pregnant, on a very low carbohydrate diet, stressed, or if you’ve been fasting longer than 18 hours. Small amounts of ketones aren’t usually too alarming but they may hint that you need to continue monitoring the effectiveness of your diabetes management program.

Ketones in moderate amounts in the urine can be a signal that your diabetes could be starting to get out of control. Left untreated, ketones in your body will continue to rise and a condition called ketoacidosis will develop. This is a life-threatening condition and requires immediate medical assistance. Other symptoms of ketoacidosis include vomiting, nausea, feeling of a mental “fog,” flushed dry skin, and a fruity breath odor. Untreated, this serious illness can cause brain swelling, coma, and even death.

If you have diabetes, it’s a good idea to keep several home testing kits around in order to occasionally monitor ketones in your urine. If you have blood glucose levels over 300 mg/dL (16.7 mmol/L) or are feeling the symptoms listed above, a quick urine ketone test could prevent advanced ketoacidosis and even save your life.

The treatment of ketoacidosis is with intravenous fluids and insulin. In a hospital setting, medical professionals can also help you identify why you developed high ketone levels in your blood. This is a key component to preventing future episodes.

If you’re pregnant and suffering from gestational diabetes, it’s important to self-test for ketones. Over the course of your pregnancy, your insulin needs may change along with your hormonal changes and lifestyle. Identifying moderate amounts of ketones in your urine early will help you understand if you need more insulin or need to adjust your diet. This keeps both mother and child safe and reduces the effect that gestational diabetes can have on the baby, including large gestational weight.