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A ketone is an organic compound that the body produces when it breaks down fat for energy. This process is known as ketosis.
Ketone testing is an essential part of managing diabetes. This is because diabetes makes it difficult for the body to regulate its levels of ketones. High ketone levels can be dangerous.
If a person has too many ketones in their blood, they may be at risk of developing diabetic ketoacidosis (DKA). DKA causes the blood to become too acidic, and the person may lose consciousness.
It is important to spot the signs of high ketones before this happens, as DKA is a medical emergency.
People can test their ketone levels using blood tests and urine tests. They can also look out for the symptoms of high ketone levels, which include thirst, nausea, confusion, and fruity-smelling breath.
In this article, we explain when to check for ketones, the types of tests available, and how to understand the results.
Ketones are a class of organic compound that the body produces when it burns fat for energy.
The blood always contains three types of ketones:
- acetoacetate (AcAc)
- 3-β-hydroxybutyrate (3HB)
As the body breaks down fats, it produces ketones. This is known as a state of ketosis. Ketosis does not cause the blood to become acidic.
Find out the differences between ketosis and ketoacidosis here.
Ketones have gained attention in recent years due to the popularity of ketogenic diets. People following a ketogenic diet consume low amounts of carbohydrates so that their body will burn fat instead of carbohydrates.
Although some individuals have experienced short-term weight loss while following the keto diet, researchers need to carry out more studies into its long-term effects.
Some experts believe that following a ketogenic diet can help with type 2 diabetes, though not everyone agrees.
When a person eats food, insulin transports the sugar to the cells to use for energy.
When a person has diabetes, their body does not produce enough insulin to transport the blood sugar, or the cells in their body may not accept it properly. This can stop the body from using the blood sugar for energy.
When the cells cannot use sugar for energy, the body will start to break down fats for energy instead. This results in an increased level of ketones in the blood.
For those with diabetes, ketone levels can build up, leading to DKA. This is when ketone levels build up, making a person’s blood pH too low or acidic.
DKA can cause someone to lose consciousness. This is known as a diabetic coma, and it is a medical emergency.
People with type 1 diabetes have the highest risk of developing DKA, but people with type 2 diabetes can develop it as well.
Testing ketone levels is an essential part of diabetes care, and checking ketone levels in the blood can help a person manage the condition and prevent DKA.
If a person experiences any of the following signs, they may have high ketone levels and should check them:
- feeling thirsty often, or having a very dry mouth
- high blood sugar levels
- frequent urination
- feeling nauseated, vomiting, or experiencing abdominal pain
- persistent tiredness
- confusion, or difficulty thinking as quickly as usual
- a fruity smell on the breath, known as keto breath
A doctor will usually advise individuals as to when and how often they should test for ketones.
The American Diabetes Association recommend that a person checks their ketone levels every 4–6 hours if their blood sugar reaches over 240 milligrams per deciliter (mg/dl).
They also recommend that people who are ill check every 4–6 hours. This includes having a cold, flu, or an infection, as illness can increase the risk of DKA.
If the person has only recently received a diagnosis for diabetes and has started taking insulin, a doctor may advise testing twice daily to make sure they are receiving the correct amount of insulin.
Two common ways to test ketone levels are urine tests and blood tests.
A ketone urine test is simple to do, and at-home testing kits are available from drugstores or online.
A urine testing kit will include a set of strips, sometimes foil wrapped. To use the test, a person should check that the test is not out of date and follow the instructions on the packaging.
Urine testing kits will usually include a color-coded strip that a person needs to dip in the urine. It will change color to indicate high levels of ketone, glucose, or protein.
Some blood glucose meters can also test ketone levels. To do a blood test using a blood glucose meter, a person should:
- put a blood ketone strip into the blood glucose meter
- prick their finger using the needle provided
- press their finger to strip to transfer a small drop of blood
- wait for the result to show on the meter
The amount of ketone in the blood can be either low/normal, medium/moderate, or high/large.
When a person has medium or high levels of ketones in their blood, doctors refer to it as ketonemia. It is a sign that a person’s diabetes may not be under control. Having high levels of ketones is also a risk factor for DKA.
If a person’s results are persistently moderate or high, a doctor may need to adjust their medication, or they may need to make some lifestyle changes.
There are three key reasons why a person would have moderate or high levels of ketones in their blood:
- Lack of insulin in the blood: Someone with diabetes may need to adjust the amount of insulin they take.
- Low blood sugar: Also known as hypoglycemia, this most often occurs in the morning when insulin levels drop.
- Not having eaten enough food: It is essential for someone with diabetes to eat regularly, so as not to let blood sugar levels drop.
If a person’s ketone levels are moderate after more than one test, or if ketone levels are high, they should consult a doctor promptly. If they have elevated ketone levels alongside any symptoms of DKA, they should seek urgent medical attention.
The body produces ketones when there is not enough insulin in the blood. Although the body usually manages these levels naturally, it is often not possible for someone with diabetes.
Regular testing is easy to do at home and should be a standard part of managing diabetes. Trying to keep blood sugar at a healthy level and being aware of the symptoms and risk factors of DKA should help keep ketone levels within an acceptable range.