What is diabetic ketoacidosis (DKA) and who is at risk?

Diabetic ketoacidosis (DKA) is a potentially life-threatening condition that most often occurs in individuals with type 1 diabetes and occasionally, but increasingly, in those with type 2 diabetes. To understand what goes wrong in DKA, it is first important to understand the role of insulin in your body. 

Why is insulin important?

Insulin is a hormone that allows a sugar called glucose to enter your cells. Glucose is produced when your body digests food and drink, and is used as a form of energy by your cells. If you have type 1 diabetes, you can’t produce insulin, which means glucose can’t enter your cells and lingers in your blood — this raises your blood glucose levels.

Dangerously high blood glucose levels can occur in individuals with type 1 diabetes for several reasons. An individual may be unaware that they have type 1 diabetes, they may be aware but aren’t taking their insulin, or they may be aware and taking their insulin but have an infection or other illness that raises certain hormones in their body, which consequently causes a rise in glucose. These hormones include cortisol, glucagon and adrenaline.

Infections cause changes in your body’s hormones, which are intended to help you fight off infection but as a consequence also raise your blood glucose levels and make insulin less effective. This can also occur in individuals with severe type 2 diabetes.

Whether there is no insulin in your body or the insulin that is present is no longer effective, the result on your cells is akin to starvation as they can’t get the energy they need by absorbing glucose. It is at this point that DKA develops.

What happens during DKA?

When your cells can’t absorb glucose, they send out signals telling your body that they need another form of energy. Your body responds by telling your fat cells to release fat. The fat travels to your liver where it is broken down into ketones, which are released into your bloodstream. Your cells absorb the ketones and use them as an alternative form of energy. This is not an inherently dangerous situation. In fact, the Atkins or keto diet is based on this principle.

The keto diet involves not eating carbohydrates or sugars and instead exclusively eating protein and fat. It is the carbohydrates and sugars in our diet that stimulate our body’s production of insulin — remove these foods from your diet and your body won’t produce insulin. This scenario is similar to the situation in type 1 diabetes where no insulin is made.

However, the key difference between an individual on a keto diet and an individual with untreated type 1 diabetes is the extent to which the body produces ketones. In untreated type 1 diabetes ketone production goes into overdrive, and as ketones are acids, this throws off the entire chemical balance inside the body.

In DKA, the level of ketones is so high that your blood becomes acidic ie you become acidotic. Acidosis interferes with all of your body’s systems and without urgent treatment results in death. Before the discovery of insulin by Canadian researchers in 1921, type 1 diabetes was universally fatal due to DKA.

DKA is, therefore, associated with high blood glucose levels, high blood acid levels (acidosis) and a history of diabetes. There is one exception to this — euglycaemic DKA (EDKA). This is a rare type of DKA and doesn’t occur in individuals with untreated diabetes but in those who are already on medication for their diabetes. In EDKA, blood glucose levels are not high but individuals still develop high ketone levels and acidosis.

Risk factors for DKA

As mentioned earlier, DKA is most common in those with undiagnosed type 1 diabetes or those with the condition who aren’t taking their insulin or have an infection but aren’t following their sick day rules. Sick day rules direct individuals with type 1 diabetes who have an infection (eg a cold) to increase the amount of insulin they take to counteract the increase in blood glucose caused by infection.

Sick day rules may be wrongly ignored because an individual feels too ill to eat and assumes that if they aren’t eating, they don’t need to take their insulin. However, during an infection, this is not the case as blood glucose levels will rise even if meals are skipped. Around one in 20 individuals with type 1 diabetes will have an episode of DKA once every year.

For individuals with type 2 diabetes, DKA is much less common but is often harder to detect until they become very unwell. This is because individuals with type 2 diabetes do not undergo daily blood glucose testing and consequently may not notice if their blood glucose levels are dangerously high.

What are the symptoms of DKA?

The main symptoms of DKA are those that also occur during hyperglycaemia (high blood sugar levels). This is described by Diabetes UK as the 4 Ts:

• Thinner — unintentionally losing weight or looking thinner than usual
• Thirsty — often feeling thirsty and not being able to quench your thirst despite drinking
• Tired — feeling more tired than usual
• Toilet — needing to urinate very often; in children, bedwetting after they have already learned to control their urination, or in babies, very heavy nappies

Another major symptom is needing to breathe deeply despite not exerting yourself. This is your body’s reaction to the high acid level of your blood. Your body tries to blow out carbon dioxide, which is another type of acid, to compensate for your high blood acid level. The breath produced will smell of acetone ie similar to nail varnish remover or pear drop sweets. If you develop these symptoms seek urgent medical attention — call 999 or get to your nearest A&E as soon as possible. 

You should also head to your nearest A&E if you notice that your blood sugar level is very high and you can’t get it under control.

Treating DKA

DKA is treated with insulin and in the UK, I have authored the national guideline on exactly how doctors should do this. From a patient perspective, if you have type 1 diabetes, your care team should provide you with ketone strips. If after testing yourself with these strips, you notice that your ketone levels are high but you don’t feel particularly unwell, then you should follow your sick day rule ie check your blood sugar level every hour, check your ketone levels every four hours, and if both are high give yourself 10% of your total daily insulin dose every two hours until your ketone and glucose levels are well-controlled. Make sure you also eat some carbohydrates to avoid your blood glucose dropping too low ie developing hypoglycaemia.

It is also important to reduce your risk of having a DKA episode by always taking your insulin as instructed, which includes following your sick day rules when you are unwell.