What is the difference between hyperglycemia and hypoglycemia?

Share on Pinterest

Blood sugar, also known as blood glucose, refers to the amount of glucose in the bloodstream. Glucose is the primary fuel source for mammals, such as humans.

The body digests foods and breaks them down into glucose, which then enters the bloodstream. The hormone insulin is responsible for allowing glucose to enter cells, which provides them with energy to function. The pancreas produces insulin and secretes it into the bloodstream to help regulate blood sugar.

Guidelines specify a typical fasting blood sugar level to be below 99 milligrams per deciliter (mg/dL). However, this level fluctuates more in a person living with diabetes. A person with diabetes should aim for a target level of 80–130 mg/dL before eating and under 180 mg/dL a couple of hours after eating.

Insulin plays an important role in calibrating blood sugar. However, if a person’s body cannot produce sufficient insulin, or their cells do not respond to insulin, it can be difficult for them to manage their blood sugar.

This can result in a person experiencing hypoglycemia or hyperglycemia. Typically, experts define hypoglycemia as blood sugar levels below 70 mg/dL.

For hyperglycemia, experts may refer to the ranges they use to diagnose diabetes. According to these ranges, they may define hyperglycemia as blood glucose greater than 125 mg/dL while fasting, and greater than 180 mg/dL 2 hours after eating. However, these ranges may vary slightly depending on factors such as a person’s age, medications they may take, and their general health.

Tracking blood glucose

People can use devices to help them monitor their blood sugar. People may use either a finger-prick test or a continuous glucose monitor (CGM).

A finger-prick test involves drawing a small drop of blood. A person uses a test strip and device to measure their glucose level.

A CGM is a wearable device a person places on their body to quickly and easily check their blood sugar. These devices can also alert a wearer when a glucose reading detects an unsafe level.

The Centers for Disease Control and Prevention (CDC) explains that some common symptoms of hyperglycemia may include:

• polydipsia, or feeling excessively thirsty
• fatigue
• polyuria, or frequent urination
• blurry vision

Symptoms of low blood sugar can present quickly. The American Diabetes Association (ADA) lists the following as some common symptoms of hypoglycemia:

• feeling shaky
• sweating, chills, and clamminess
• irritability
• confusion
• rapid heart rate
• feeling lightheaded
• feeling weak or having no energy
• tingling or numbness in the lips, tongue, or cheeks
• coordination problems
• seizures

Evidence notes that many factors can influence blood sugar and can cause it to rise or fall. For example, the following may result in an increase in blood glucose:

• eating large amounts of food, particularly foods high in carbohydrates
• dehydration
• not administering a sufficient amount of diabetes medication
• changes in hormone levels, such as from illness, stress, pain, or menstrual periods
• side effects from certain medications, such as steroids or antipsychotic medications
• periods of physical inactivity

Alternatively, the following factors may cause blood sugar to drop:

• eating less food than the body needs, skipping meals, or consuming foods with fewer carbohydrates
• administering too much diabetes medication
• consuming alcohol, particularly on an empty stomach
• being more physically active than is typical
• side effects from certain medications

Certain triggers may also affect blood sugar. For example, factors such as drinking coffee, losing sleep, having gum disease, and extreme heat can all influence blood sugar and make it more difficult to manage.

To keep blood sugar within a suitable range and help prevent potential complications, a person should carefully manage their blood sugar.

Managing blood sugar typically involves various methods, such as regularly checking blood sugar, being mindful of symptoms, and correcting blood glucose when necessary with either diabetes medication or carbohydrates.

An effective strategy to help manage blood sugar is known as managing the “ABCs” of diabetes. This refers to:

• an A1C test, which measures a person’s average blood sugar level
• blood pressure
• cholesterol
• smoking

Additionally, other useful methods may include:

• Regular exercise: Physical activity can provide many health benefits, including helping to manage blood glucose.
• Following a diabetes meal plan: Consuming a variety of nutritious foods from all food groups, and avoiding certain foods, may help improve overall health. Foods a person may wish to reduce or avoid include those that are fried, high in salt, or have added sugars.
• Medication: A person should follow the guidelines from their diabetes care team and take their diabetes medication as advised.

Hyperglycemia refers to high blood sugar. Hypoglycemia describes low blood sugar. When blood sugar is outside typical ranges, a person may experience various symptoms.

Health conditions such as diabetes can make it difficult to manage blood sugar. As such, it is important for a person to carefully monitor their blood glucose level. A person can correct high blood sugar with diabetes medications, and low blood sugar by consuming fast-acting glucose.