Diabetic ketoacidosis (DKA) can develop when the body is unable to break down the glucose in the bloodstream because of a severe lack of insulin. This forces the body to break down fats, which produces acidic waste products known as ketones. Excessive levels of ketones (ketosis) can lead to ketoacidosis and have life-threatening consequences.

DKA develops primarily because of infection or illness, or when people fail to control their diabetes, such as missing or skipping insulin doses. Ketoacidosis may also develop as a result of complications of pregnancy, and it may be caused by eating disorders.

DKA may lead to diabetic coma or even death, if untreated. Immediate emergency treatment is required. With proper medical treatment, patients can completely recover and prevent DKA from occurring again.

DKA most commonly affects people with type 1 diabetes, but it may affect those with type 2 diabetes or other forms of diabetes. According to the American Diabetes Association (ADA), women have a 50 percent higher risk for DKA than men. The ADA estimates that this condition is responsible for about 10 percent of all diabetes-related deaths in patients under the age of 45. Sometimes DKA occurs in people whose diabetes has not yet been diagnosed.  

Diabetic ketoacidosis develops because of the combination of three factors:

• A severe lack of insulin
• Very high levels of glucose (severe hyperglycemia)
• Very high levels of ketones (severe ketosis)

Normally, the body forms energy by breaking down glucose, which is moved through the bloodstream by insulin. However, in type 1 diabetes, the pancreas no longer produces insulin. When insulin is not available, the body will find other sources to transform into energy. This lack of energy causes muscle cells to starve, and the body is forced to use fat, and not glucose, to form energy. The breakdown of fat leaves ketones as a waste product.

Some ketones are released through the urine, but many remain. These extra ketones build up in the blood, causing ketoacidosis. However, only when ketoacidosis is caused by complications related to diabetes is it referred to as diabetic ketoacidosis. There are other forms of ketoacidosis, including alcohol ketoacidosis, brought on by high consumption of alcohol, and starvation ketoacidosis, caused by a lack of food. Diets low in carbohydrates can cause ketosis by forcing the body to burn fats rather than glucose for energy, but dietary ketosis in nondiabetics rarely leads to ketoacidosis.

People with diabetes can check their level of ketones with a simple urine test involving a test strip (like a blood testing strip). Some glucose meters also monitor ketones. The ADA recommends that people with diabetes monitor their ketones:

• When sick or under stress
• During pregnancy
• When blood glucose is high, typically:
  
• • Above 240 milligrams per deciliter (mg/dL) with type 1 diabetes
  • Above 300 mg/dL with other forms of diabetes
  • Or as advised by their physician

It is important for pregnant women to test their ketone levels every day. When diabetic patients are sick and their glucose level is higher than 240 mg/dL, the ADA advises that ketones be checked every four to six hours. Ketone buildup can cause nausea, and it can easily be mistaken as being caused by illness. Parents of children with diabetes should check their children’s ketone levels when they complain of a stomachache.

Though physical activity is normally an important part of managing diabetes, people should not exercise when their levels of ketones and glucose are high, according to the ADA. Instead they are advised to call their physician.

Diabetic individuals are advised to have their physician create a sick-day plan for them in advance of potential problems. When people with diabetes become sick, glucose can rise and ketosis may develop, and they can become even sicker. It is important to monitor glucose and ketones more than usual when sick, as these higher levels may require additional insulin.

Although DKA develops slowly, once vomiting occurs the condition may worsen in a matter of hours. Without treatment, DKA can lead to a number of potentially life-threatening complications, including:

• Cerebral edema. Swelling of the brain.
  
  
• Cardiac arrhythmia (or dysrhythmia). An abnormal heart rhythm.
  
  
• Hyperkalemia. High level of potassium in the blood. This can cause arrhythmia or even cardiac arrest, in which the heart stops beating.
  
  
• Hypokalemia. Low level of potassium in the blood. This can cause arrhythmia, muscle weakness or cramping, extreme thirst (polydipsia) and possibly even paralysis of the lungs.
  
  
• Arterial thrombosis. Blood clot in an artery.
  
  
• Disseminated intravascular coagulation (DIC). A reduction of blood-clotting factors.
  
  
• Adult respiratory distress syndrome (ARDS). A rare condition affecting smokers and involving rapid respiratory failure.
  
  
• Pneumomediastinum. Air found in the mediastinum, the area between the lungs in the chest.
  
  
• Pulmonary embolus. A sudden blockage affecting the lungs, such as a blood clot.
  
  
• Pulmonary edema. An accumulation and swelling of fluid in the lungs.
  
  
• Subcutaneous emphysema. A condition in which gas is present within the tissue under the skin covering the chest wall. It results in a crackling bulge under the skin’s surface.
  
  
• Heart attack.
  
  
• Kidney failure.
  
  
• Rhabdomyolysis (a breakdown of muscle fibers.) This releases the muscle fibers’ contents into circulating blood. This content may be toxic and damage the kidneys.
  
  
• Shock.
  
  
• Infection.

People with diabetes may also be at risk for a condition known as hyperosmolar hyperglycemic nonketotic state (HHNS), which occurs when severe hyperglycemia is combined with dehydration, typically without ketosis. HHNS is usually found in elderly individuals. Unlike diabetic ketoacidosis, HHNS occurs more often in patients with type 2 diabetes and is uncommon in those with type 1 diabetes. The mortality rate from both conditions has plunged in recent decades, according to the U.S. Centers for Disease Control and Prevention.