Symptoms of High Blood Sugar: Everything You Need To Know
Whenever you bite into a piece of fruit or eat a bowl of pasta, you provide your body with the energy and nutrients needed to stay healthy. One of the most essential nutrients is glucose, a type of sugar. It’s a primary power source that travels in the bloodstream to cells throughout your body. Typically, our bodies carefully regulate glucose levels, ensuring they don’t get too high or too low. But sometimes, as happens in people with diabetes, the body is unable to control those levels effectively. Hyperglycemia occurs when the level of blood glucose gets too high. Hyperglycemia can affect people of any age and can cause a range of symptoms, including excessive thirst, hunger, fatigue, and/or an urge to urinate more significant amounts than usual. If left untreated for an extended period of time, it can lead to severe complications, such as eye damage, kidney problems, and heart disease, among others. Fortunately, treatments are available that can help prevent hyperglycemia and control blood glucose levels.
What is hyperglycemia?
Hyperglycemia is when the blood glucose level is higher than usual. Sometimes called “high blood sugar,” it commonly affects people who have diabetes mellitus, but it can also develop in non-diabetics.
Glucose is the primary source of energy for all cells in our bodies. It comes from the foods we eat, mainly carbohydrates. When food reaches the stomach, it is broken down into different parts–one of which is glucose. The intestines absorb the glucose, which enters the bloodstream and circulates the body.
Typically, the body uses insulin to move glucose from the blood into cells, lowering glucose and providing cells with energy.
Hyperglycemia can occur when the body does not produce enough insulin or respond to insulin correctly. In both cases, glucose stays in the blood instead of being sent to the cells, and as a result, blood glucose levels remain elevated. If more glucose enters the bloodstream–if you eat carbohydrate-rich food, for example–the blood glucose levels climb even higher.
In some cases, people with diabetes who have hyperglycemia can develop a complication called diabetic ketoacidosis (DKA). In this condition, the cells cannot access glucose. Instead, the body gets energy by breaking down fats. This process produces compounds called ketones, which build up in the blood, causing it to become acidic. DKA is a life-threatening condition. (DKA is most commonly associated with type 1 diabetes but can occur in people with type 2 as well.)
In people with type 2 diabetes, very high blood glucose levels can lead to a life-threatening condition called hyperosmolar hyperglycemic state (HHS), which causes profound dehydration and a change in mental status.
What causes hyperglycemia?
Hyperglycemia most commonly affects people who have diabetes. In type 1 diabetes, the body does not make enough insulin. In type 2 diabetes, the body produces adequate insulin, but the cells do not respond appropriately. This is called insulin resistance.
For people with diabetes, hyperglycemia can be triggered by:
- Eating too many carbohydrates
- Not exercising enough
- Not taking enough insulin medication (for type 1 diabetes) or other medications that regulate blood glucose levels
Hyperglycemia can also be caused by:
- Medications such as corticosteroids, thiazide diuretics, beta-blockers, and antipsychotics
- Certain conditions affect the pancreas, which produces insulin
- Medical conditions that can cause insulin resistance, such as Cushing’s syndrome and
- acromegaly
- Pregnancy
- Stress
What are the risk factors for hyperglycemia?
Certain factors or conditions increase the risk for hyperglycemia, including:
- Obesity or being overweight
- Family history of type 2 diabetes
- Personal history of gestational diabetes
- Prediabetes (when blood glucose levels are high but not high enough to be diagnosed as diabetes)
What are the symptoms of hyperglycemia?
Symptoms of hyperglycemia include:
- Urinating large amounts
- Excessive thirst
- Feeling tired
- Frequent hunger
- Dry mouth
- Weight loss
- Blurred vision
- Recurrent infections (e.g., urinary infections, skin infections)
- Wounds (cuts, scrapes) that heal slowly
In addition to the symptoms of hyperglycemia, people with DKA may also experience:
- Deep, rapid breathing
- Fruity-smelling breath
- Headache
- Nausea and vomiting
- Stomach pain
- Change in mental status
- Loss of consciousness, coma
HHS can cause the following symptoms:
- Dehydration
- Change in mental status
- Loss of consciousness, coma
How is hyperglycemia diagnosed?
A diagnosis of hyperglycemia usually involves reviewing your medical history, undergoing a physical exam, and performing blood tests.
The doctor will ask about your symptoms and whether you have a family history of diabetes or other risk factors associated with hyperglycemia. He or she will conduct a physical exam.
Ultimately, though, blood tests that measure blood glucose levels are necessary to diagnose hyperglycemia definitively. For a “fasting blood glucose” (FBG) test, you must abstain from eating for 8 hours prior to the test. Other blood tests may include a hemoglobin A1C (glycated hemoglobin) and an oral glucose tolerance test (OGTT).
How is hyperglycemia treated?
The treatment depends on the cause of hyperglycemia and may include the following:
- Insulin. For people with type 1 diabetes, insulin is the primary treatment for hyperglycemia. Sometimes, it may also be used to treat people with type 2 diabetes.
- Glucose-lowering medications. Various drugs, such as metformin, may be used to lower blood glucose levels.
- Glucose monitoring. People with diabetes should monitor their blood glucose levels as instructed by their doctor.
- Lifestyle changes. People with diabetes can reduce the risk of developing hyperglycemia or treat existing hyperglycemia by regular exercise, following a nutritious diet, and maintaining a healthy weight.
DKA and HHS are medical emergencies. They are treated with intravenous fluids, electrolytes, and insulin.
What is the outlook for people who have hyperglycemia?
In general, transient hyperglycemia does not cause long-term problems. But if it persists, it can lead to serious complications, including eye problems, kidney damage, nerve damage, and cardiovascular disease.
However, with appropriate treatment and regular monitoring of blood glucose levels, people can reduce the risk of hyperglycemia, lower their chances of having severe complications, and live healthy lives.
What makes Yale Medicine unique in its treatment of hyperglycemia?
“The Yale Diabetes Center provides individualized care for adults with hyperglycemia whether it is transient (such as medication-induced), prediabetes, or type 1 or type 2 diabetes,” says Beatrice Lupsa, MD, a Yale Medicine endocrinologist who specializes in type 1 and type 2 diabetes. “Our staff includes endocrinologists, mid-level practitioners, and a dietitian. Our multidisciplinary approach ensures people with blood glucose problems get self-management skills and knowledge to achieve optimal long-term blood glucose control. We focus on lifestyle interventions, including healthy diet and exercise. Our patients have access to the most advanced medical care, including the latest medications and technologies to prevent hyperglycemic complications and maintain better health throughout their lives.”