Diabetic ketoacidosis is a potentially fatal complication of diabetes that occurs when you have much less insulin than your body needs. This problem causes the blood to become acidic and the body to become dangerously dehydrated. Diabetic ketoacidosis can occur when diabetes is not treated adequately, or it can occur during times of serious sickness.
To understand this illness, you need to understand the way your body powers itself with sugar and other fuels. Foods we eat are broken down by the body, and much of what we eat becomes glucose (a type of sugar), which enters the bloodstream. Insulin helps glucose to pass from the bloodstream into body cells, where it is used for energy. Insulin normally is made by the pancreas, but people with type 1 diabetes (insulin-dependent diabetes) don't produce enough insulin and must inject it daily.
Your body needs a constant source of energy. When you have plenty of insulin, your body cells can get all the energy they need from glucose. If you don't have enough insulin in your blood, your liver is programmed to manufacture emergency fuels. These fuels, made from fat, are called ketones (or ketoacids). In a pinch, ketones can give you energy. However, if your body stays dependent on ketones for energy for too long, you soon will become ill. Ketones are acidic chemicals that are toxic at high concentrations.
In diabetic ketoacidosis, ketones build up in the blood, seriously altering the normal chemistry of the blood and interfering with the function of multiple organs. They make the blood acidic, which causes vomiting and abdominal pain. If the acid level of the blood becomes extreme, ketoacidosis can cause falling blood pressure, coma and death.
Ketoacidosis is always accompanied by dehydration, which is caused by high levels of glucose in the blood. Glucose builds up in the blood if there is not enough insulin to move glucose into your cells. During an episode of ketoacidosis, it is common for blood sugar to rise to a level over 400 milligrams per deciliter. When blood sugar levels are so high, some sugar "overflows" into the urine. As sugar is carried away in the urine, water, salt and potassium are drawn into the urine with each sugar molecule, and your body loses large quantities of your fluid and electrolytes, which are minerals that play a crucial role in cell function. As this happens, you produce much more urine than normal. Eventually it may become impossible for you to drink enough fluids to keep up with amounts that you urinate. Vomiting caused by the blood's acidity also contributes to fluid losses and dehydration.
People with type 1 diabetes are at risk of diabetic ketoacidosis. If you have type 1 diabetes, ketoacidosis can occur because you have stopped taking your insulin injections or because your insulin dose is too low. It can be triggered by an infection or severe physical stress, such as an injury or surgery, because your body can need more insulin than usual during these stresses. Ketoacidosis rarely occurs in people with type 2 diabetes. In most people who have type 2 diabetes, blood insulin levels usually do not get low enough to signal the liver to make ketones.
In about 25% of children with diabetes, symptoms from ketoacidosis are the first sign that they have diabetes.