From A1C to BG: A Clear Glossary of Terms for Persons with Diabetes

18 Sep 2025 By Danielle M. Shilling, M.D.

From A1C to BG: A Clear Glossary of Terms for Persons with Diabetes

Living with diabetes involves managing a complex set of factors, from blood glucose levels to medication dosages. Navigating this landscape can be overwhelming, especially when you're bombarded with unfamiliar terms and acronyms. This article serves as a comprehensive glossary to help people with diabetes better understand and manage their condition. We’ll cover essential terms, explain their significance, and provide practical context for how they relate to daily diabetes management. Let’s dive in and clarify some of the key terminology!

The Importance of Understanding Diabetes Terminology

Accurate comprehension of diabetes-related terms isn't merely about speaking the lingo; it directly impacts the ability to make informed decisions about your health. It facilitates better communication with your healthcare team, empowers you to self-manage effectively, and ultimately leads to improved health outcomes. Imagine trying to adjust your insulin dosage without understanding what 'basal rate' means or interpreting your A1C results without knowing their significance. This glossary is designed to bridge those knowledge gaps. How To Regulate Blood Sugar For Better Energy And Weight Loss

Key Terms Explained

We'll begin with the essentials, explaining common terms related to blood glucose, insulin, medications, and complications, followed by more advanced terms as we progress.

A1C (Glycated Hemoglobin)

A1C, or Glycated Hemoglobin, represents your average blood glucose level over the past 2-3 months. This test measures the percentage of hemoglobin (a protein in red blood cells that carries oxygen) that is coated with glucose. The higher your average blood glucose levels, the higher your A1C. It is a key indicator of how well your diabetes is being controlled over time.

Ideal Range: Generally, for people with diabetes, the target A1C is below 7%. However, this target should be individualized and determined in consultation with your healthcare provider.
Significance: Regularly monitoring A1C helps assess the effectiveness of your treatment plan and guides necessary adjustments.

Example:

If your A1C is 8%, it means that, on average, approximately 8% of your hemoglobin is coated with glucose. This indicates poorer blood glucose control compared to someone with an A1C of 6.5%.

Blood Glucose (BG)

Blood Glucose (BG), also referred to as blood sugar, is the amount of glucose present in your blood. Glucose is the primary source of energy for your body’s cells and comes from the food you eat. People with diabetes need to monitor their blood glucose levels regularly to ensure they are within the target range. Blood Sugar And Weight Loss The Missing Link To Your Success

Target Range: Generally, target blood glucose ranges are:
- Before meals (Pre-prandial): 80-130 mg/dL
- Two hours after starting a meal (Post-prandial): Less than 180 mg/dL
Significance: Regular monitoring allows you to adjust your diet, exercise, and medication to maintain stable blood glucose levels and prevent complications.

Table: Understanding Blood Glucose Levels

Basal Insulin

Basal Insulin is a long-acting type of insulin that provides a continuous, steady background level of insulin in the body. It helps keep blood glucose levels stable between meals and during sleep.

Examples: Insulin glargine (Lantus, Basaglar, Toujeo), insulin detemir (Levemir), and insulin degludec (Tresiba).
Significance: Basal insulin mimics the natural insulin release of the pancreas in individuals without diabetes, ensuring that the body has a constant supply of insulin to manage glucose production by the liver.

Bolus Insulin

Bolus Insulin is a rapid-acting type of insulin taken before meals to cover the carbohydrates you are about to eat. It helps prevent blood glucose levels from rising too high after eating. The Link Between Insulin Resistance And Regulating Your Blood Sugar

Examples: Insulin lispro (Humalog), insulin aspart (NovoLog), and insulin glulisine (Apidra).
Significance: Bolus insulin is crucial for matching the insulin dose to carbohydrate intake, allowing for more flexibility in meal timing and food choices.

Carbohydrate Counting

Carbohydrate Counting is a meal planning technique where you track the amount of carbohydrates you consume at each meal and adjust your bolus insulin dose accordingly.

How it works: You learn to identify carbohydrate-containing foods and their serving sizes, then calculate the total carbohydrate intake for a meal. Based on your insulin-to-carbohydrate ratio, you determine the appropriate insulin dose.
Significance: This method offers more precise control over blood glucose levels and allows for greater flexibility in meal planning.

Continuous Glucose Monitoring (CGM)

Continuous Glucose Monitoring (CGM) is a device that tracks blood glucose levels in real-time throughout the day and night. A small sensor inserted under the skin measures glucose levels in the interstitial fluid (fluid around the cells).

Benefits:
- Provides a complete picture of glucose trends, showing how levels change over time.
- Alerts you to high and low glucose levels, even overnight.
- Helps identify patterns related to food, exercise, and medication.
Examples: Dexcom, Freestyle Libre, and Medtronic Guardian.

Diabetic Ketoacidosis (DKA)

Diabetic Ketoacidosis (DKA) is a serious complication of diabetes that occurs when the body doesn't have enough insulin to use glucose for energy, so it starts breaking down fat instead. This process produces ketones, which can build up to dangerous levels in the blood.

Symptoms: Excessive thirst, frequent urination, nausea, vomiting, abdominal pain, weakness, shortness of breath, and a fruity-smelling breath.
Significance: DKA is a medical emergency and requires immediate treatment to prevent severe complications and potential death.

Exercise and Diabetes

Exercise and Diabetes - Physical activity impacts blood glucose levels in a myriad of ways. Regular exercise increases insulin sensitivity, which helps cells use glucose more efficiently, reducing the need for as much external insulin or medication. It also lowers blood pressure and improves cholesterol levels, contributing to overall cardiovascular health. However, exercise can also lead to hypoglycemia (low blood sugar) or hyperglycemia (high blood sugar) depending on the intensity, duration, and timing of insulin injections or medication intake.

Recommendation: Aim for at least 150 minutes of moderate-intensity aerobic exercise per week, spread out over several days. Consult with a healthcare professional to create a personalized exercise plan and to adjust medication or insulin doses accordingly.
Precautions:
- Monitor blood glucose before, during, and after exercise to understand how your body responds.
- Carry a fast-acting source of carbohydrates to treat hypoglycemia if it occurs.
- Stay hydrated to maintain proper blood volume and prevent dehydration.

Foot Care

Foot Care is a critical aspect of diabetes management due to the potential for nerve damage (neuropathy) and poor circulation, which can increase the risk of foot ulcers, infections, and even amputation. High blood glucose levels over time can damage nerves, leading to a loss of sensation in the feet. Reduced blood flow makes it harder for sores and cuts to heal.

Key Practices:
- Daily foot inspections: Check your feet daily for cuts, blisters, redness, swelling, or any other abnormalities.
- Wash your feet daily: Use lukewarm water and mild soap, drying them thoroughly, especially between the toes.
- Moisturize your feet: Apply lotion to prevent dry skin, but avoid putting it between the toes.
- Wear properly fitting shoes: Choose comfortable, supportive shoes and avoid walking barefoot.
- Cut toenails straight across: This prevents ingrown toenails, which can lead to infections.
- See a podiatrist regularly: Schedule regular foot exams to identify and address any potential problems early.

Glucagon

Glucagon is a hormone that raises blood glucose levels. It's used as an emergency treatment for severe hypoglycemia (very low blood sugar) when someone is unable to take sugar orally.

How it works: Glucagon stimulates the liver to release stored glucose into the bloodstream, quickly increasing blood glucose levels.
Significance: Family members, caregivers, and close friends of people with diabetes should be trained on how to administer glucagon in case of a hypoglycemic emergency.
Administration: Glucagon is available as an injectable kit or a nasal spray. Follow the instructions provided with the product.

Hyperglycemia

Hyperglycemia refers to high blood glucose levels. It occurs when there is not enough insulin in the body or when the body cannot use insulin properly.

Symptoms: Frequent urination, increased thirst, blurred vision, fatigue, and slow-healing sores.
Causes: Missing insulin doses, eating too many carbohydrates, illness, stress, and inactivity.
Management: Adjusting insulin or medication doses, increasing physical activity, and following a balanced diet.

Hypoglycemia

Hypoglycemia refers to low blood glucose levels. It occurs when there is too much insulin in the body relative to the amount of available glucose.

Symptoms: Shakiness, sweating, dizziness, confusion, hunger, irritability, rapid heartbeat, and loss of consciousness.
Causes: Taking too much insulin, skipping meals, exercising without adjusting insulin, and alcohol consumption.
Management: Consuming fast-acting carbohydrates such as glucose tablets, juice, or regular soda. If severe, requires glucagon administration.

Insulin Resistance

Insulin Resistance is a condition where the body's cells do not respond effectively to insulin. This means that more insulin is needed to move glucose from the bloodstream into the cells.

Causes: Obesity, physical inactivity, genetics, certain medications, and other medical conditions.
Significance: Insulin resistance can lead to prediabetes and type 2 diabetes, as the pancreas eventually struggles to produce enough insulin to overcome the resistance.
Management: Lifestyle modifications such as weight loss, regular exercise, and a healthy diet can improve insulin sensitivity. Medications may also be prescribed.

Ketones

Ketones are chemicals produced when the body breaks down fat for energy because it doesn't have enough insulin to use glucose. High levels of ketones in the blood can lead to diabetic ketoacidosis (DKA).

Testing: Ketones can be measured in the urine or blood using ketone testing strips or meters.
Significance: Checking for ketones is particularly important when blood glucose levels are high (above 250 mg/dL) or during illness.
Management: If ketones are present, it's essential to drink plenty of fluids and contact your healthcare provider immediately.

Lipohypertrophy

Lipohypertrophy refers to the development of lumps or swelling under the skin caused by repeated insulin injections in the same area.

Prevention: Rotating injection sites regularly helps prevent lipohypertrophy.
Significance: Injecting into areas affected by lipohypertrophy can lead to erratic insulin absorption and poor blood glucose control.
Management: Avoid injecting into affected areas until the tissue has healed.

Metabolic Syndrome

Metabolic Syndrome is a cluster of conditions that occur together, increasing the risk of heart disease, stroke, and type 2 diabetes. These conditions include:

High blood pressure
High blood glucose
High triglycerides
Low HDL cholesterol ("good" cholesterol)
Excess abdominal fat
Significance: Managing metabolic syndrome through lifestyle changes and medication can significantly reduce the risk of developing diabetes and cardiovascular disease.

Neuropathy

Neuropathy is nerve damage that can occur as a complication of diabetes. High blood glucose levels over time can damage nerves throughout the body.

Symptoms: Numbness, tingling, pain, and weakness in the hands and feet.
Types: Peripheral neuropathy (affecting the extremities), autonomic neuropathy (affecting internal organs), and focal neuropathy (affecting a single nerve).
Management: Controlling blood glucose levels, pain management medications, and foot care.

Oral Hypoglycemic Agents

Oral Hypoglycemic Agents (OHAs) are medications taken by mouth to lower blood glucose levels in people with type 2 diabetes. These medications work through different mechanisms, such as:

Increasing insulin production: Sulfonylureas, meglitinides.
Improving insulin sensitivity: Metformin, thiazolidinediones (TZDs).
Slowing carbohydrate absorption: Alpha-glucosidase inhibitors.
Increasing incretin hormones: DPP-4 inhibitors, GLP-1 receptor agonists (though some GLP-1s are injectable).

Prediabetes

Prediabetes is a condition where blood glucose levels are higher than normal but not high enough to be diagnosed as type 2 diabetes.

Significance: Prediabetes is a warning sign that you are at high risk of developing type 2 diabetes.
Diagnosis: Diagnosed through A1C, fasting blood glucose, or oral glucose tolerance test.
Management: Lifestyle changes such as weight loss, regular exercise, and a healthy diet can prevent or delay the onset of type 2 diabetes.

Renal Threshold

Renal Threshold refers to the concentration of a substance (such as glucose) in the blood at which the kidneys begin to excrete it into the urine. For glucose, the renal threshold is typically around 180 mg/dL.

Significance: When blood glucose levels exceed this threshold, glucose spills over into the urine, leading to increased urination and fluid loss.

Standard Deviation (SD) and Coefficient of Variation (CV)

Standard Deviation (SD) and Coefficient of Variation (CV) are statistical measures used to assess the variability of blood glucose levels over a period of time.

SD: Measures the average deviation of individual glucose values from the mean (average) glucose value. A lower SD indicates less variability.
CV: Expresses the SD as a percentage of the mean glucose value. A lower CV indicates greater stability of blood glucose levels.
Significance: Healthcare providers use SD and CV to evaluate the effectiveness of diabetes management plans and make adjustments as needed to minimize glucose variability.

Time in Range (TIR)

Time in Range (TIR) refers to the percentage of time that a person’s blood glucose levels are within a target range. This range is typically between 70-180 mg/dL.

Significance: TIR is a valuable metric for assessing blood glucose control and is increasingly used in clinical practice.
Goal: A TIR of 70% or greater is generally considered a good target.
Benefits: Maximizing TIR is associated with reduced risk of diabetes complications.

Understanding Target Ranges

Each of the terms above hinges on understanding personalized target ranges. While general guidelines exist, remember that your healthcare provider will tailor these targets based on individual factors like age, overall health, pregnancy status, and the presence of other medical conditions. The goal is to achieve the best possible blood glucose control while minimizing the risk of hypoglycemia. Always clarify any uncertainties about your targets with your diabetes care team.

Practical Applications and Tips

Knowing the terminology is one thing; applying it is another. Here are a few practical scenarios and tips to help you integrate these terms into your daily diabetes management.

Scenario 1: Adjusting Insulin for Exercise: Suppose your blood glucose is 150 mg/dL before a workout. Knowing that exercise can lower blood glucose, you might reduce your bolus insulin dose slightly to prevent hypoglycemia during or after your activity.
Scenario 2: Interpreting CGM Data: If your CGM shows that your glucose levels consistently rise after lunch, you might adjust your bolus insulin dose or modify your carbohydrate intake at that meal.
Scenario 3: Sick Day Management: During illness, blood glucose levels can be unpredictable. Checking for ketones and staying hydrated are crucial to prevent DKA. You may need to adjust your insulin doses based on your glucose levels, consulting your healthcare provider if necessary.

Communication is Key

Armed with this glossary, you are better equipped to engage in meaningful conversations with your healthcare team. Don't hesitate to ask questions and seek clarification whenever needed. Effective communication ensures that you receive personalized guidance and support to manage your diabetes effectively.

Conclusion

Managing diabetes requires a comprehensive understanding of various terms and concepts. This glossary provides a solid foundation for people with diabetes to navigate their condition with confidence. By mastering this terminology and working closely with your healthcare team, you can take control of your health and live a full and active life. Remember, knowledge is power, and the more you understand about diabetes, the better equipped you'll be to manage it successfully.