People often ask what it means when their meter flashes “test ketones”.
Ketones are produced in the blood from the break down of fat. Fat is used for fuel when the body can’t burn glucose.
Situation # 1: The body needs more insulin
In people with type 1 diabetes, ketones are made because there is a relative lack of insulin, which is needed to burn glucose for fuel. In this situation, their blood sugars are usually high. So some meters will give a prompt to test ketones if the reading is over 15 mmol/L.
In this case, ketones are a sign of danger - a sign that the body needs more insulin.
A build up of ketones can cause a condition called “ketoacidosis” which can be a life-threatening situation. The body operates within a very narrow range of pH or acidity. Ketones change the delicate pH balance in the blood and cause people to go into a coma and even die if this condition is not treated. The usual cause is forgetting to take insulin or perhaps taking insulin that is no longer active (like if it gets too hot or too cold). Another cause can be the flu or any acute illness that make the body need more insulin. People on an insulin pump may be particularly prone to going into ketoacidosis faster than people on injections as once the pump is disconnected (or if the site is not working) there is no body “store” of insulin. Dehydration for any cause can also tip people into ketoacidosis, for example, vomiting with the flu.
Once ketones build up, the body tries to compensate by increasing the breathing rate. The breath as it breathes off the ketones has a “fruity” smell. Often there will be stomach pain and vomiting. This last symptom can be misunderstood as the “flu” and ignored. Once this happens or if the sugars and ketones remain high, it is critical to be treated in a hospital setting. Sometimes a “correction” scale of extra insulin is used that correlates to ketone testing that is part of a plan for sick days and should be carefully assessed by the diabetes team.
Situation # 2: Not eating enough
Ketones can also form when someone has not eaten enough food and is in a “starving state”. In this case blood sugars are normal or low and can happen to people without diabetes but can also happen to people with diabetes if they are not consuming enough calories. The usual treatment for this is to eat. The group of people who do test for ketones on a regular basis who may not be on insulin are pregnant women whom have gestational diabetes. This is to ensure that they are getting enough calories with their diabetic meal plan. Usually, they test first thing in the morning as it is the longest time without food.
Testing for ketones:
One can test for ketones in the urine or the blood. The urine ketone strips can be bought without a prescription and turn a dark colour after 15 seconds once dipped into urine. The amount of ketones is indicated by how dark the strip turns. This is usually the way a woman with gestational diabetes tests her urine. Another method which is more accurate in distinguishing the type of ketones, that is, either lack of insulin or starvation, is to test the blood. There are some meters that have strips, very similar to blood glucose testing strips, that will indicate the level of ketones. People with type 1 diabetes and particularly children and their families, are often taught this type of ketone testing.