Why Is My Blood Sugar High? 7 Surprising Factors Beyond Food

18 Sep 2025 By Mikel Prieto, M.D.

Why Is My Blood Sugar High? 7 Surprising Factors Beyond Food

High blood sugar, also known as hyperglycemia, is a common concern for people with diabetes. While diet certainly plays a crucial role in managing blood sugar levels, many other factors can significantly impact your glucose readings. This article explores seven surprising reasons your blood sugar might be high, even when you're watching what you eat. Understanding these factors can empower you to better manage your health and work effectively with your healthcare provider.

Why High Blood Sugar Matters

Before diving into the surprising factors, it’s essential to understand why managing blood sugar is critical. Chronically high blood sugar can lead to several serious health complications, including:

Heart disease: Elevated glucose can damage blood vessels and increase the risk of atherosclerosis.
Nerve damage (neuropathy): High blood sugar can impair nerve function, leading to pain, numbness, and other issues.
Kidney damage (nephropathy): Prolonged hyperglycemia can damage the kidneys, potentially leading to kidney failure.
Eye damage (retinopathy): High blood sugar can damage the blood vessels in the retina, increasing the risk of vision loss.
Increased risk of infections: Hyperglycemia can weaken the immune system, making you more susceptible to infections.

Keeping your blood sugar within the target range recommended by your doctor is vital for preventing or delaying these complications.

1. Stress: The Silent Blood Sugar Thief

Stress is more than just a feeling of overwhelm; it's a physiological response that can wreak havoc on your blood sugar. When you're stressed, your body releases hormones like cortisol and adrenaline. These hormones prepare you for "fight or flight" by increasing glucose production, ensuring you have the energy to respond to the perceived threat. However, if stress is chronic, these hormones can keep your blood sugar consistently elevated.

How to Combat Stress-Induced Hyperglycemia:

Mindfulness and Meditation: Even a few minutes of daily meditation can lower cortisol levels. Apps like Headspace and Calm offer guided sessions.
Regular Exercise: Physical activity helps burn off excess glucose and reduces stress hormones. Aim for at least 30 minutes of moderate-intensity exercise most days of the week.
Adequate Sleep: Sleep deprivation increases cortisol levels. Aim for 7-9 hours of quality sleep each night.
Deep Breathing Exercises: Simple deep breathing techniques can quickly calm the nervous system and reduce stress. Try inhaling deeply for four seconds, holding for seven seconds, and exhaling for eight seconds.
Social Support: Connecting with friends and family can help buffer the effects of stress.

Example:

A 2018 study published in the Journal of Diabetes Science and Technology found that individuals with type 2 diabetes who practiced mindfulness meditation had significantly lower blood glucose levels and improved well-being compared to those who did not.

2. Dehydration: The Blood Sugar Concentrator

Dehydration can lead to higher blood sugar readings because it concentrates the glucose in your blood. When you're properly hydrated, your kidneys can efficiently flush out excess glucose through urine. However, when you're dehydrated, your kidneys conserve water, leading to a higher concentration of glucose in your bloodstream.

How to Stay Hydrated and Manage Blood Sugar:

Drink Water Throughout the Day: Aim for at least eight glasses of water daily. Adjust this based on your activity level and climate.
Monitor Urine Color: Pale yellow urine indicates good hydration. Darker urine suggests you need to drink more fluids.
Eat Hydrating Foods: Fruits and vegetables with high water content, such as watermelon, cucumbers, and spinach, can contribute to your daily fluid intake.
Avoid Sugary Drinks: Sodas, juices, and sweetened beverages can spike blood sugar and contribute to dehydration.
Drink Electrolyte-Rich Drinks: After intense exercise or in hot weather, consider drinking electrolyte-rich beverages to replenish lost fluids and minerals.

Real-World Example:

Sarah, who has type 2 diabetes, noticed her blood sugar was consistently high despite following her diet plan. After consulting her doctor, she realized she wasn't drinking enough water, especially during the hot summer months. By increasing her water intake, she saw a significant improvement in her blood sugar levels.

3. Dawn Phenomenon: The Early Morning Surge

The dawn phenomenon is a natural rise in blood sugar that occurs in the early morning hours, typically between 3 AM and 8 AM. This phenomenon is caused by hormonal changes in the body, including the release of growth hormone, cortisol, and adrenaline. These hormones signal the liver to release glucose into the bloodstream, providing energy for the day ahead. For people with diabetes, this natural process can lead to unexpectedly high blood sugar readings in the morning. Cgm Vs Bgm Choosing The Right Blood Glucose Monitoring System For You

Managing the Dawn Phenomenon:

Adjust Medication: Talk to your doctor about adjusting the timing or dosage of your diabetes medication to better cover the morning surge.
Eat a Low-Carb Dinner: Eating a dinner that's lower in carbohydrates can help minimize the amount of glucose available for release during the night.
Regular Exercise: Physical activity, especially in the evening, can improve insulin sensitivity and help regulate blood sugar levels.
Consistent Sleep Schedule: Maintaining a consistent sleep schedule can help regulate hormonal fluctuations and minimize the dawn phenomenon.
Monitor Blood Sugar Levels: Regularly check your blood sugar levels throughout the night and in the morning to identify patterns and adjust your management plan accordingly.

Research Insight:

According to the American Diabetes Association, the dawn phenomenon is common in people with both type 1 and type 2 diabetes. Understanding this phenomenon is crucial for effectively managing blood sugar levels throughout the day.

4. Certain Medications: The Unexpected Side Effect

Certain medications, even those not directly related to diabetes, can raise blood sugar levels as a side effect. Some common culprits include:

Corticosteroids (e.g., prednisone): Used to treat inflammation, allergies, and autoimmune diseases.
Decongestants (e.g., pseudoephedrine): Found in many over-the-counter cold and allergy medications.
Diuretics (e.g., hydrochlorothiazide): Used to treat high blood pressure and edema.
Beta-blockers (e.g., metoprolol): Used to treat high blood pressure and heart conditions.
Antidepressants (e.g., some SSRIs): Certain antidepressants can affect blood sugar levels.

What to Do:

Review Medications with Your Doctor: Discuss all medications you're taking, including over-the-counter drugs and supplements, with your doctor.
Monitor Blood Sugar Closely: If you start a new medication, monitor your blood sugar more frequently to identify any potential impact.
Consider Alternatives: If possible, explore alternative medications that may have less of an impact on blood sugar levels. Do not discontinue medication without consulting your doctor.
Adjust Diabetes Management Plan: Your doctor may need to adjust your diabetes medication or lifestyle plan to compensate for the effects of other medications.

Case Study:

John, who has type 2 diabetes, started taking prednisone for a severe allergic reaction. He noticed his blood sugar levels spiked significantly, even though he was following his usual diet and exercise routine. After discussing the issue with his doctor, they adjusted his diabetes medication temporarily to manage the side effects of prednisone.

5. Artificial Sweeteners: The Controversial Substitute

While often marketed as a healthier alternative to sugar, some studies suggest that artificial sweeteners may have a negative impact on blood sugar control. Although they don't directly raise blood sugar in the same way that sugar does, some research indicates they can alter gut bacteria and affect insulin sensitivity, potentially leading to higher blood sugar levels in the long run.

Considerations for Using Artificial Sweeteners:

Be Mindful of Overall Intake: Even if artificial sweeteners don't directly spike blood sugar, they can contribute to cravings for sweet foods and potentially disrupt metabolic processes.
Choose Wisely: Some artificial sweeteners, like stevia and erythritol, may have less of an impact on blood sugar than others, such as aspartame and sucralose.
Listen to Your Body: Pay attention to how your body responds to different artificial sweeteners and adjust your intake accordingly.
Focus on Whole Foods: Emphasize whole, unprocessed foods with natural sweetness, such as fruits and vegetables, rather than relying heavily on artificial sweeteners.

Research Highlight:

A study published in Nature found that artificial sweeteners can alter gut microbiota in a way that may lead to glucose intolerance in some individuals. This highlights the importance of considering the potential long-term effects of artificial sweetener consumption.

6. Gum Disease: The Inflammatory Connection

Gum disease (periodontitis) is a chronic inflammatory condition that affects the gums and bone supporting your teeth. Research suggests a strong link between gum disease and diabetes, with each condition potentially worsening the other. The inflammation associated with gum disease can increase insulin resistance and make it more difficult to control blood sugar levels.

Managing Gum Disease for Better Blood Sugar Control:

Practice Good Oral Hygiene: Brush your teeth at least twice a day, floss daily, and use an antiseptic mouthwash.
Regular Dental Checkups: Visit your dentist regularly for professional cleanings and to monitor for signs of gum disease.
Control Blood Sugar Levels: Maintaining good blood sugar control can help prevent and manage gum disease.
Quit Smoking: Smoking increases the risk of gum disease and other health problems.
Consider Professional Treatment: If you have gum disease, seek treatment from a dentist or periodontist to reduce inflammation and prevent further complications.

Expert Insight:

The American Academy of Periodontology emphasizes the importance of good oral hygiene and regular dental care for people with diabetes. Managing gum disease can significantly improve blood sugar control and overall health. Simple Habits For Better Blood Sugar Balance And All Day Energy

7. Inactivity: The Metabolic Slowdown

Physical inactivity can significantly impact blood sugar levels by reducing insulin sensitivity and slowing down metabolism. When you're active, your muscles use glucose for energy, helping to lower blood sugar. Regular exercise also improves your body's response to insulin, allowing it to more effectively transport glucose from the bloodstream into cells.

Incorporating Activity into Your Routine:

Aim for Regular Exercise: Strive for at least 150 minutes of moderate-intensity aerobic exercise per week, such as brisk walking, swimming, or cycling.
Include Strength Training: Incorporate strength training exercises at least twice a week to build muscle mass, which can further improve insulin sensitivity.
Break Up Sedentary Time: Avoid prolonged periods of sitting by standing up and moving around every 30 minutes.
Find Activities You Enjoy: Choose activities that you find enjoyable and sustainable to make exercise a regular part of your lifestyle.
Start Slowly: If you're new to exercise, start slowly and gradually increase the intensity and duration of your workouts.

Scientific Evidence:

A meta-analysis published in JAMA Internal Medicine found that both aerobic and resistance exercise are effective in improving glycemic control in people with type 2 diabetes. This underscores the importance of incorporating regular physical activity into your diabetes management plan.

Understanding the various factors beyond food that can influence blood sugar is crucial for effective diabetes management. By addressing these surprising contributors, you can gain better control over your blood sugar levels and reduce your risk of long-term complications. Remember to work closely with your healthcare team to develop a personalized management plan that addresses your individual needs and circumstances. Consistent monitoring, proactive management, and a holistic approach to health will empower you to live a healthier, more fulfilling life with diabetes.