A Person with Diabetes' Guide to Insulin and Blood Sugar Control

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

A Person with Diabetes' Guide to Insulin and Blood Sugar Control

Living with diabetes requires a careful balancing act, and understanding insulin and its role in blood sugar control is paramount. Whether you're newly diagnosed or have been managing diabetes for years, this comprehensive guide offers valuable insights into effectively using insulin to maintain healthy blood sugar levels. We'll delve into the different types of insulin, how they work, how to administer them correctly, and lifestyle adjustments that complement insulin therapy.

What is Insulin and Why is it Important for People with Diabetes?

Insulin is a hormone produced by the pancreas that allows glucose (sugar) from the food we eat to enter our cells and provide them with energy. In people with Type 1 diabetes, the pancreas doesn't produce insulin. In Type 2 diabetes, the body either doesn't produce enough insulin or doesn't use insulin efficiently (insulin resistance).

Without sufficient insulin, glucose builds up in the bloodstream, leading to hyperglycemia (high blood sugar). Over time, high blood sugar can damage various organs, including the heart, kidneys, eyes, and nerves. Insulin therapy aims to replace or supplement the body's insulin production, helping to keep blood sugar levels within a healthy range and preventing long-term complications. Hypoglycemia Vs Hyperglycemia Spotting Low Vs High Blood Sugar

Key Functions of Insulin:

Transports Glucose: Enables glucose to move from the bloodstream into cells for energy.
Storage of Glucose: Facilitates the storage of excess glucose in the liver and muscles as glycogen for later use.
Regulation of Blood Sugar: Helps maintain a stable blood sugar level, preventing both hyperglycemia and hypoglycemia.

Understanding Different Types of Insulin

Insulin isn't a one-size-fits-all solution. Several types of insulin are available, each with a different onset, peak, and duration of action. The type of insulin prescribed depends on individual needs, lifestyle, and blood sugar patterns.

Here’s a breakdown of common insulin types:

| Insulin Type | Onset | Peak | Duration | Usage Example | |------------------|------------------|------------------|------------------|------------------------------------------------| | Rapid-Acting | 15 minutes | 1-2 hours | 2-4 hours | Taken before meals to cover carbohydrate intake | | Short-Acting | 30 minutes | 2-3 hours | 3-6 hours | Taken before meals, slightly earlier | | Intermediate-Acting | 1-2 hours | 4-12 hours | 12-18 hours | Provides background insulin coverage | | Long-Acting | 1-2 hours | No pronounced peak| 20-24+ hours | Provides consistent background insulin | | Ultra Long-Acting | 6 hours | Minimal Peak | 36+ hours | Basal insulin coverage | | Pre-Mixed | Varies depending on components | Varies depending on components | Up to 24 hours | Simplifies dosing by combining different insulin types |

Rapid-Acting Insulin: This type of insulin starts working very quickly and is usually taken just before or right after a meal to cover the rise in blood sugar from the food. Examples include lispro (Humalog), aspart (Novolog), and glulisine (Apidra).
Short-Acting Insulin (Regular Insulin): Short-acting insulin takes about 30 minutes to start working, so it needs to be injected about 30 minutes before a meal. It typically lasts for 3-6 hours. Humulin R and Novolin R are common brands.
Intermediate-Acting Insulin: This type of insulin has a longer duration of action and is often used to provide background insulin coverage between meals and overnight. NPH insulin (Humulin N, Novolin N) is an example. It's important to note that NPH insulin has a peak effect, which can increase the risk of low blood sugar if not managed properly.
Long-Acting Insulin: Long-acting insulins provide a steady level of insulin for 24 hours or more. They are often used as a basal insulin to cover the body's basic insulin needs. Examples include glargine (Lantus, Basaglar, Toujeo) and detemir (Levemir). These insulins have a more predictable and peakless profile than NPH insulin, reducing the risk of hypoglycemia.
Ultra Long-Acting Insulin: This type can work for over 36 hours and is useful for providing steady insulin levels in basal insulin needs. An example is Insulin Degludec.
Pre-Mixed Insulin: These insulins combine a rapid- or short-acting insulin with an intermediate-acting insulin in a fixed ratio. They offer convenience but may not provide as much flexibility as using individual insulin types.

Consult with your doctor or certified diabetes educator to determine which type of insulin is best suited for your individual needs. They will consider your blood sugar patterns, lifestyle, and overall health to create a personalized insulin regimen.

Methods of Insulin Delivery

Insulin can be administered in several ways, each with its own advantages and disadvantages. The most common methods include:

Syringes: Traditional method using a needle and syringe to inject insulin.
Insulin Pens: Convenient and discreet, pre-filled or refillable pens with adjustable doses.
Insulin Pumps: Small, computerized devices that deliver a continuous, controlled dose of insulin through a catheter inserted under the skin.
Inhalable Insulin: Rapid-acting insulin inhaled before meals (e.g., Afrezza).

Here's a more detailed look at each method:

1. Syringes:

Pros: Affordable, widely available, allows for precise dosing.
Cons: Requires manual injection, can be less convenient than pens or pumps.

2. Insulin Pens:

Pros: More convenient and discreet than syringes, easy to use on the go, adjustable doses, some come pre-filled.
Cons: More expensive than syringes, may not be as precise for very small doses.

3. Insulin Pumps:

Pros: Delivers precise and customized insulin doses, can improve blood sugar control, eliminates the need for multiple daily injections, can be programmed to adjust insulin delivery based on activity levels.
Cons: More expensive than other methods, requires training and commitment to manage the pump, risk of pump malfunction or infusion site problems.

4. Inhalable Insulin:

Pros: Rapid onset of action, convenient alternative to injections for mealtime insulin.
Cons: Not suitable for everyone (e.g., people with lung conditions), requires proper technique for inhalation, can be more expensive than other methods.

Important Considerations When Choosing a Delivery Method:

Lifestyle: Consider your activity level, travel habits, and daily routine.
Cost: Weigh the initial cost of the device and ongoing supply costs.
Comfort and Convenience: Choose a method that you feel comfortable using and that fits easily into your lifestyle.
Blood Sugar Control: Discuss your blood sugar goals with your doctor and choose a method that will help you achieve them.

Proper Injection Technique and Site Rotation

The way you inject insulin can affect how quickly and effectively it works. Here are some essential tips for proper injection technique:

Wash your hands: Always wash your hands thoroughly with soap and water before injecting insulin.
Prepare the injection site: Clean the injection site with an alcohol swab and allow it to dry.
Pinch the skin: Pinch up a fold of skin at the injection site, especially if you are thin, to avoid injecting into the muscle.
Insert the needle: Insert the needle at a 45- to 90-degree angle, depending on the needle length and your body size.
Inject the insulin: Push the plunger all the way in and hold for a few seconds to ensure all the insulin is delivered.
Release the skin and withdraw the needle: Release the pinched skin and gently withdraw the needle.
Do not rub the injection site: Avoid rubbing the injection site, as this can affect insulin absorption.
Dispose of the needle properly: Use a sharps container to safely dispose of used needles and syringes.

Why Site Rotation is Important:

Prevents Lipohypertrophy: Repeated injections in the same area can cause lipohypertrophy (lumps of fatty tissue under the skin), which can affect insulin absorption.
Improves Insulin Absorption: Rotating injection sites ensures consistent insulin absorption and helps to prevent unpredictable blood sugar fluctuations.
Reduces Discomfort: Site rotation can minimize discomfort and skin irritation.

Recommended Injection Sites:

Abdomen: The abdomen is a preferred site because insulin is absorbed consistently from this area. Use the area at least two inches away from the navel.
Thighs: The front and outer sides of the thighs are also suitable injection sites.
Upper Arms: The back of the upper arms can be used, but it may be difficult to reach this area on your own.
Buttocks: The upper, outer quadrants of the buttocks are also acceptable injection sites.

Rotation Strategies:

Systematic Rotation: Divide each injection site (abdomen, thighs, arms, buttocks) into quadrants and rotate within each quadrant before moving to the next.
Daily Rotation: Choose a different injection site each day.
Weekly Rotation: Use the same general area (e.g., abdomen) for a week, rotating within that area, before moving to another area.

Monitoring Blood Sugar Levels: The Key to Insulin Management

Regular blood sugar monitoring is crucial for effective insulin management. By tracking your blood sugar levels, you can understand how different factors (such as food, exercise, and stress) affect your blood sugar and adjust your insulin doses accordingly. Hyperglycemia Explained Your Action Plan For High Blood Sugar Levels

Tools for Monitoring Blood Sugar:

Blood Glucose Meter (Glucometer): A small, portable device that measures the glucose level in a drop of blood.
Continuous Glucose Monitor (CGM): A sensor inserted under the skin that continuously tracks glucose levels and transmits the data to a receiver or smartphone.

Frequency of Monitoring:

The frequency of blood sugar monitoring depends on your individual needs, the type of insulin you use, and your overall blood sugar control. Your doctor or certified diabetes educator will advise you on how often to check your blood sugar. As a general guideline:

People using multiple daily injections (MDI) of insulin: Check blood sugar before meals and before bedtime, and occasionally 1-2 hours after meals.
People using an insulin pump: Check blood sugar several times a day, including before meals, before bedtime, and as needed to monitor for highs or lows.
People using long-acting insulin: Check blood sugar before breakfast, before dinner, and before bedtime.

Target Blood Sugar Ranges:

Target blood sugar ranges vary from person to person. Your doctor will set individualized goals for you. General guidelines are:

Before meals: 80-130 mg/dL
2 hours after meals: Less than 180 mg/dL
HbA1c: Less than 7% (This is a measure of average blood sugar over the past 2-3 months)

What to do with Blood Sugar Readings:

Log your results: Keep a record of your blood sugar readings, along with information about your food intake, activity levels, and insulin doses.
Analyze your patterns: Look for patterns in your blood sugar readings to identify factors that are affecting your blood sugar control.
Adjust your insulin doses: Work with your doctor or certified diabetes educator to adjust your insulin doses based on your blood sugar patterns.
Take action: If your blood sugar is consistently outside of your target range, take action to correct it. This may involve adjusting your insulin doses, changing your diet, or increasing your physical activity.

Diet, Exercise, and Lifestyle Modifications

While insulin is a critical component of diabetes management, it's important to remember that diet, exercise, and other lifestyle factors also play a significant role in blood sugar control.

Dietary Recommendations:

Focus on whole, unprocessed foods: Choose fruits, vegetables, whole grains, lean proteins, and healthy fats.
Limit sugary drinks and processed foods: These can cause rapid spikes in blood sugar.
Control portion sizes: Eating too much food can lead to high blood sugar levels.
Carbohydrate Counting: Many people with diabetes use carbohydrate counting to match their insulin doses to the amount of carbohydrates they consume. This involves estimating the grams of carbohydrates in a meal and adjusting the insulin dose accordingly. Your doctor or certified diabetes educator can help you learn how to count carbohydrates.
Consistent Meal Timing: Eating meals at regular intervals can help to stabilize blood sugar levels.

Exercise Recommendations:

Aim for at least 150 minutes of moderate-intensity aerobic exercise per week: This could include brisk walking, swimming, or cycling.
Incorporate strength training exercises 2-3 times per week: Strength training helps to improve insulin sensitivity and build muscle mass.
Monitor your blood sugar before, during, and after exercise: Exercise can lower blood sugar levels, so it's important to monitor your blood sugar and adjust your insulin doses or carbohydrate intake as needed.
Be aware of delayed hypoglycemia: Sometimes, blood sugar levels can drop several hours after exercise. Be prepared to treat low blood sugar if it occurs.

Other Lifestyle Modifications:

Stress Management: Stress can raise blood sugar levels. Find healthy ways to manage stress, such as exercise, yoga, or meditation.
Adequate Sleep: Lack of sleep can affect insulin sensitivity and blood sugar control. Aim for 7-8 hours of sleep per night.
Regular Checkups: See your doctor and certified diabetes educator regularly to monitor your blood sugar control and adjust your treatment plan as needed.

Managing Hypoglycemia (Low Blood Sugar)

Hypoglycemia (low blood sugar) is a common complication of insulin therapy. It occurs when blood sugar levels drop too low, usually below 70 mg/dL. Hypoglycemia can be caused by: Hyperglycemia How To Safely Lower High Blood Sugar Levels

Taking too much insulin:
Skipping or delaying meals:
Exercising without adjusting insulin or food intake:
Drinking alcohol:

Symptoms of Hypoglycemia:

Shakiness
Sweating
Dizziness
Confusion
Irritability
Hunger
Headache
Blurred vision
Difficulty concentrating
Loss of consciousness (in severe cases)

Treatment for Hypoglycemia:

If you experience symptoms of hypoglycemia, check your blood sugar level. If it is below 70 mg/dL, follow the "15-15 rule":

Consume 15 grams of fast-acting carbohydrates: Examples include:
- 4 ounces of juice or regular soda
- 3-4 glucose tablets
- 1 tablespoon of honey or sugar
Wait 15 minutes and recheck your blood sugar:
If your blood sugar is still below 70 mg/dL, repeat steps 1 and 2.
Once your blood sugar is above 70 mg/dL, eat a snack or meal to prevent it from dropping again.

Severe Hypoglycemia:

If you become unconscious or are unable to treat yourself, you will need assistance. Your family members, friends, and coworkers should be trained on how to administer glucagon, a hormone that raises blood sugar levels. Glucagon is available as an injection or nasal spray.

Preventing Hypoglycemia:

Monitor your blood sugar regularly:
Take your insulin as prescribed:
Eat meals and snacks on time:
Adjust your insulin doses or carbohydrate intake when exercising:
Avoid drinking alcohol on an empty stomach:
Wear a medical alert bracelet or necklace that identifies you as having diabetes:

Dealing with Hyperglycemia (High Blood Sugar)

Hyperglycemia (high blood sugar) occurs when blood sugar levels are too high, usually above your target range. Hyperglycemia can be caused by:

Not taking enough insulin:
Eating too much food:
Being inactive:
Illness or infection:
Stress:

Symptoms of Hyperglycemia:

Frequent urination
Excessive thirst
Blurred vision
Fatigue
Headache

Treatment for Hyperglycemia:

If you experience symptoms of hyperglycemia, check your blood sugar level. If it is above your target range, take the following steps:

Drink plenty of fluids: This will help to flush out excess glucose from your body.
Take a correction dose of insulin: Your doctor or certified diabetes educator will provide you with instructions on how to calculate a correction dose of insulin.
Check your blood sugar regularly: Monitor your blood sugar level every 2-3 hours until it returns to your target range.
Identify the cause of the hyperglycemia: Determine what may have caused your blood sugar to rise. This will help you to prevent it from happening again.
Contact your doctor if your blood sugar remains high or if you experience symptoms of diabetic ketoacidosis (DKA).

Preventing Hyperglycemia:

Take your insulin as prescribed:
Eat a healthy diet:
Exercise regularly:
Manage stress:
Monitor your blood sugar regularly:

Insulin Adjustment Strategies for Various Situations

Effectively managing diabetes often requires adjusting insulin dosages based on various factors. Here are a few common scenarios and strategies for adjusting your insulin:

Exercise: Exercise usually lowers blood sugar, so you may need to reduce your insulin dose before or after physical activity. Consult with your doctor to determine the appropriate adjustment based on the intensity and duration of the exercise. You might also need to consume extra carbohydrates to prevent hypoglycemia.
Illness: Illness can raise blood sugar levels due to stress hormones and decreased activity. You may need to increase your insulin dose during illness, but it's crucial to monitor your blood sugar more frequently and stay hydrated. Never stop taking insulin, even if you're not eating, unless instructed by your doctor.
Travel: Traveling can disrupt your routine and affect your blood sugar control. Be sure to adjust your insulin schedule based on time zone changes, pack extra insulin and supplies, and monitor your blood sugar more frequently.
Menstruation: Some women experience fluctuations in blood sugar levels during their menstrual cycle, often requiring adjustments in insulin doses.
Changes in Diet: Changes in your dietary habits, such as eating more or fewer carbohydrates, will require adjustments to your insulin doses. It's important to work with your healthcare team to develop a meal plan that is tailored to your individual needs and to learn how to adjust your insulin doses accordingly.

When to Seek Professional Medical Advice

While self-management is crucial for diabetes control, it's equally important to know when to seek professional medical advice. Contact your doctor or certified diabetes educator if you experience any of the following:

Frequent episodes of hypoglycemia or hyperglycemia:
Unexplained changes in blood sugar levels:
Symptoms of DKA or HHS (hyperosmolar hyperglycemic state): These are serious complications of diabetes that require immediate medical attention.
Difficulty managing your blood sugar, despite making lifestyle changes and adjusting your insulin doses:
Any concerns about your diabetes management plan:

The Future of Insulin Therapy

Insulin therapy continues to evolve, with ongoing research and development aimed at improving blood sugar control, reducing the risk of hypoglycemia, and enhancing the overall quality of life for people with diabetes. Some promising areas of research include:

Smart insulin: These "glucose-responsive" insulins release insulin only when blood sugar levels are high, reducing the risk of hypoglycemia.
Inhaled insulin: Advances in inhaler technology are making inhaled insulin more convenient and effective.
Pancreas transplantation: For some people with Type 1 diabetes, pancreas transplantation can restore insulin production and eliminate the need for insulin injections.
Artificial pancreas systems (closed-loop systems): These systems combine a continuous glucose monitor, an insulin pump, and sophisticated algorithms to automatically adjust insulin delivery based on real-time blood sugar levels.

Key Takeaways for Effective Insulin and Blood Sugar Control

Mastering insulin therapy and blood sugar control is an ongoing journey that requires education, vigilance, and a collaborative approach with your healthcare team. By understanding the different types of insulin, proper injection techniques, the importance of blood sugar monitoring, and the role of diet and exercise, you can effectively manage your diabetes and live a healthy, fulfilling life. Always consult with your doctor or certified diabetes educator for personalized advice and guidance.

Remember these key points:

Understand your insulin: Know the type of insulin you're taking, its onset, peak, and duration.
Monitor your blood sugar regularly: This is the key to understanding how your body responds to insulin, food, and exercise.
Adjust your insulin doses as needed: Be prepared to adjust your insulin doses based on various factors, such as exercise, illness, and travel.
Work closely with your healthcare team: Your doctor and certified diabetes educator can provide personalized guidance and support.
Be patient and persistent: Managing diabetes is a lifelong journey. There will be challenges along the way, but with education, perseverance, and the right support, you can achieve good blood sugar control and live a healthy, fulfilling life.