In people with diabetes, a diabetic coma occurs when severe levels of either high or low uncontrolled blood sugar are not corrected. If treated quickly, a person will make a rapid recovery from a diabetic coma.
However, diabetic coma can be fatal or result in brain damage. It is important for people with diabetes to control their blood sugars and know what to do when their blood sugar levels are not within their target range.
The severe symptoms of uncontrolled blood sugar that can come before a diabetic coma include vomiting, difficulty breathing, confusion, weakness, and dizziness.
Recovery from diabetic coma
If a diabetic coma is not treated within a couple of hours of it developing, it can cause irreversible brain damage. If no treatment is received, a diabetic coma will be fatal.
In addition, having blood sugar levels that continue to be too low or too high can be bad for long-term health. This remains true even if they do not develop into diabetic coma.
Recognizing the early signs of low or high blood sugar levels and regular monitoring can help people with diabetes keep their blood sugar levels within the healthy range. Doing so will also reduce the risk of associated complications and diabetic coma.
What is diabetes?
Diabetes is a long-term condition in which the body is unable to control the level of a sugar called glucose in the blood. Diabetes is caused by either a lack of insulin, the body's inability to use insulin correctly, or both.
Uncontrolled diabetes can cause a person's blood sugar levels to rise and fall significantly.
In people who don't have diabetes, insulin usually ensures that excess glucose is removed from the bloodstream. It does this by stimulating cells to absorb the glucose they need for energy from the blood. Insulin also causes any remaining glucose to be stored in the liver as a substance called glycogen.
The production of insulin increases when blood glucose levels are high, for example after a meal. The body produces less insulin when blood sugar levels have returned to normal.
If blood glucose levels fall too low, a second hormone called glucagon is produced that stimulates the liver to release the glucose it has stored as glycogen.
In type 1 diabetes, the cells of the pancreas that produce insulin are damaged. The pancreas is then unable to produce insulin. Blood glucose levels are not controlled and rise to damagingly high levels unless people take insulin on a daily basis.
In addition, the lack of insulin means that the body's cells cannot absorb glucose from the blood. Instead, they get the energy they need to survive by burning fat. The breakdown of fat results in the release of waste byproducts called ketones.
Type 1 diabetes usually starts in childhood or adolescence though it can occur at any age. People with this form of diabetes require insulin injections to control blood glucose levels for the rest of their lifetime.
In type 2 diabetes, the pancreas still produces insulin, at least early in the disease process, but not in sufficient amounts to keep blood glucose at a normal level. This type of diabetes usually occurs later in life, although can occur at any age, and is particularly common among people who are obese.
Type 2 diabetes is managed with diet and exercise, with medications added as needed to help control blood sugar levels.
Causes of diabetic coma
There are three main causes of diabetic coma. Two causes are associated with type 1 diabetes, and one is associated with type 2 diabetes.
In type 1 diabetes, diabetic coma can be caused by very low blood glucose levels, also known as hypoglycemia, or high blood ketone levels, also known as diabetic ketoacidosis.
In type 2 diabetes, diabetic coma can be caused by low blood sugar or is caused by very high blood glucose levels, also known as hyperglycemic hyperosmolar syndrome.
A diabetic coma is lengthy unconsciousness caused by altered blood sugar levels.
Hypoglycemia is when blood glucose levels are too low (under 70 mg/dL). The brain uses glucose for energy. If there is not enough glucose in the blood for the brain to continue to work properly, it closes down. This causes the person to go into a coma.
Hypoglycemia usually only occurs in people who are being treated with insulin, although it can occur with oral medications that increase insulin levels in the body. Too much medication, too little food, too much exercise, or a combination of these factors can cause blood glucose levels fall too low.
When this occurs, the person may feel shaky, sweaty, or tired. They may also develop dizziness or a headache. Eating or drinking a source of glucose will bring blood glucose levels back into the healthy range, and the person will feel better almost immediately.
If the symptoms are overlooked or not experienced at all, the individual will become unconscious. Prolonged unconsciousness due to altered blood sugar levels is called a diabetic coma.
A diabetic coma can be rapidly reversed by giving glucose and injecting glucagon. Treatment must be given within a couple of hours before the brain suffers permanent damage.
Diabetic ketoacidosis is a serious complication of type 1 diabetes that arises when levels of ketones in the blood become too high.
The levels of ketones in the blood rise excessively if an individual is using fat rather than sugar as an energy source. This occurs in people with type 1 diabetes for a variety of reasons, including not receiving enough insulin or illness. People with diabetic ketoacidosis will also have high levels of glucose in their blood since the sugar cannot go from the blood and into the cells.
The body tries to reduce the high glucose levels by allowing glucose to leave the body in the urine. However, this also causes the body to lose more water.
Diabetic ketoacidosis will make a person feel tired and very thirsty and cause them to urinate more frequently. It can also cause an upset stomach with nausea and vomiting, flushed and dry skin, a fruity smell to the breath, and shortness of breath.
Diabetic ketoacidosis can lead to diabetic coma if left untreated. It is a medical emergency requiring prompt treatment with insulin and fluid. If diabetic ketoacidosis is not treated effectively, it will lead to death.
Hyperglycemic hyperosmolar syndrome
Careful monitoring of blood sugar levels is crucial to preventing diabetic coma.
Diabetic hyperglycemic hyperosmolar syndrome is a condition that is usually seen in elderly people with type 2 diabetes that is not adequately controlled. It occurs when blood glucose levels are extremely high.
As with diabetic ketoacidosis, a person with hyperglycemic hyperosmolar syndrome will feel tired, very thirsty, and will need to urinate more frequently.
The two conditions can be differentiated by a simple blood test. Unlike in diabetic ketoacidosis, a person with hyperosmolar syndrome will have normal blood ketone levels.
Hyperglycemic hyperosmolar syndrome will cause a diabetic coma if left untreated. In addition, hyperglycemic hyperosmolar syndrome may also lead to blood vessel complications, such as a heart attack, stroke, or blood clots.
Hyperosmolar syndrome is initially treated by giving saline solution into the veins. This will also help to lower blood glucose levels. Insulin may be needed if glucose levels do not return to normal with rehydration, however.