Will drinking lots of water help lower A1C? Understanding the vital role of hydration in diabetes management

Multiple studies have shown a strong link between low water intake and a higher risk of developing hyperglycemia, or high blood sugar. But will drinking lots of water help lower A1C directly, or is it a supportive tool that works alongside other vital lifestyle changes?

Quick Summary

Staying properly hydrated assists the kidneys in flushing out excess glucose, but it is not a primary treatment for lowering A1C. A complete strategy involves diet, exercise, and medical oversight for effective blood sugar management.

Key Points

• Hydration's Indirect Role: Water does not directly reduce the glucose-bound hemoglobin (A1C), but it helps manage blood glucose concentration in the short term.

• Kidney Function Support: By staying hydrated, you help your kidneys effectively flush out excess glucose from the bloodstream via urine.

• Water is a Tool, Not a Cure: Water is a supportive element of diabetes care, not a replacement for a balanced diet, exercise, and prescribed medication to manage A1C.

• Dehydration Increases Blood Glucose: When you are dehydrated, the concentration of glucose in your blood rises, causing higher-than-usual blood sugar readings.

• Risk of Over-hydration: Drinking excessive amounts of water can be harmful, leading to a serious electrolyte imbalance called hyponatremia.

• Lifestyle is Primary for A1C: Sustainable A1C reduction comes from a holistic approach focusing on diet, physical activity, and medical treatment.

• Flavor Water, Not Sugar: Add fruit or herbs to water for flavor instead of consuming high-sugar beverages that spike blood glucose.

• Consult a Doctor: Always discuss hydration targets and diabetes management with a healthcare professional, especially if you have other medical conditions.

The Relationship Between Hydration and Blood Sugar

The A1C test provides a crucial metric for diabetes management by measuring your average blood glucose levels over the past two to three months. This is accomplished by measuring the percentage of hemoglobin—a protein in your red blood cells—that has glucose attached to it. While a snapshot blood glucose reading shows your level at a specific moment, the A1C reflects your overall glucose control over time, making it an excellent long-term indicator.

Proper hydration is fundamentally linked to blood sugar because the water in your bloodstream dilutes the concentration of glucose. When you are dehydrated, the fluid volume in your blood decreases, causing the glucose to become more concentrated. This can result in a higher blood glucose reading, even if the total amount of sugar in your system hasn't changed. While drinking water can help rehydrate your blood and temporarily lower a high blood glucose concentration, it is not a substitute for insulin or other diabetes medications.

How Proper Hydration Supports A1C Management

There are several key ways that drinking enough water contributes to better blood sugar control:

• Aids Kidney Function: When blood glucose levels are high, your kidneys work harder to filter and eliminate the excess sugar through urine. Drinking sufficient water supports this process, ensuring your kidneys can function efficiently without added strain.
• Helps Dilute Blood Glucose: Staying well-hydrated prevents the blood from becoming overly concentrated with glucose, mitigating the impact of dehydration on blood sugar spikes.
• Reduces Risk of Complications: Chronic dehydration can stress the kidneys and other organs, which can accelerate the progression of diabetes-related complications, such as kidney disease. Proper hydration is a simple way to protect your kidneys and overall cardiovascular health.
• Curbing Unhealthy Choices: Sometimes, the body mistakes thirst for hunger. Reaching for water can help you stay satiated, preventing you from choosing sugary or high-carb snacks that can negatively impact blood sugar levels.
• Lowers Stress Hormones: Dehydration can prompt the release of stress hormones, like vasopressin, which can, in turn, signal the liver to produce more glucose. Staying hydrated helps manage stress and supports stable blood sugar.

The Limitations of Water for A1C Reduction

It is crucial to understand that while hydration is a vital supportive tool, it will not single-handedly lower a high A1C into the normal range. Relying solely on water to manage diabetes is not effective and can be dangerous. A high A1C indicates a long-term pattern of high blood sugar that requires a more comprehensive approach. Forcing yourself to drink an excessive amount of water can also be harmful, potentially leading to a dangerous electrolyte imbalance called hyponatremia. This condition is particularly risky for individuals with certain health issues, such as congestive heart failure or kidney disease, and can cause symptoms ranging from nausea to confusion.

Comprehensive Strategies for A1C Reduction

For a meaningful and lasting impact on your A1C, hydration must be paired with other evidence-backed strategies. Here is a comparison of how hydration fits into a broader diabetes management plan:

Factor	Mechanism of Action	Impact on A1C	Limitations
Hydration (Water)	Assists kidneys in flushing out glucose; prevents blood concentration caused by dehydration.	Indirect/Supportive: Supports kidney function and helps manage blood glucose concentration, but doesn't directly reduce long-term averages.	Insufficient on its own; excessive intake can be harmful.
Diet (Complex Carbs, Fiber)	High-fiber, complex carbs slow sugar absorption; reduces postprandial glucose spikes.	Direct: Significantly impacts daily and long-term blood sugar levels, directly influencing A1C.	Requires portion control and consistent meal planning.
Exercise	Increases insulin sensitivity; muscles use glucose for energy during and after activity.	Direct: Reduces overall blood sugar levels, contributing to a lower A1C.	Requires consistency; timing relative to food/medication needs monitoring.
Medication/Insulin	Directly regulates blood glucose levels by supplementing or enhancing natural processes.	Direct & Primary: Provides the most targeted and immediate control over blood sugar for those with diagnosed diabetes.	Requires strict adherence and medical supervision; doesn't address lifestyle causes.
Weight Management	Reduces insulin resistance, allowing cells to use glucose more effectively.	Direct: Can profoundly improve glycemic control and lower A1C, especially for those with Type 2 diabetes.	Can be challenging and requires long-term commitment.

Practical Hydration Tips

Incorporating good hydration habits into your daily routine is simple and effective. Here are some strategies to try:

• Start Your Day with Water: Drink a glass of water first thing in the morning to rehydrate your body after sleep.
• Carry a Reusable Bottle: Keep a water bottle with you throughout the day as a constant reminder to sip regularly.
• Set Reminders: Use smartphone apps or set alarms to prompt regular water intake, especially if you aren't sensitive to thirst signals.
• Flavor Your Water: If plain water isn't appealing, add slices of lemon, cucumber, or mint for a refreshing twist without added sugar.
• Choose Water Over Sugary Drinks: Opt for water instead of juices, sodas, or other sugary beverages that cause blood glucose spikes.
• Stay Hydrated with Foods: Consume water-rich fruits and vegetables like cucumbers, watermelon, strawberries, and celery.

Conclusion

Drinking water is a healthy and important habit that supports blood sugar management by preventing dehydration and aiding kidney function. However, it is not a magic bullet for lowering A1C. A high A1C is a sign of long-term elevated blood sugar that requires a multi-faceted approach involving a balanced diet, regular exercise, and, in most cases, medication under a doctor's supervision. The most effective strategy for managing your A1C and overall health is to use hydration as part of a comprehensive lifestyle plan, rather than relying on it as a sole solution. Always consult your healthcare provider to create a personalized diabetes management plan that is safe and effective for your individual needs.

References

1. Zoe. (2024, March 19). Does Drinking Water Lower Blood Sugar?.
2. MD Anderson Cancer Center. (2023, November 7). 6 tips to lower your blood sugar.
3. MedlinePlus. (2025, May 20). Hemoglobin A1C (HbA1c) Test.
4. Healthline. (2024, May 20). 14 Natural Strategies to Lower Blood Sugar Levels.
5. Mya Care. (2024, April 24). WATER AND DIABETES: BENEFITS AND DAILY INTAKE RECOMMENDATIONS.
6. Verywell Health. (2025, April 22). Diet to Lower A1C and Blood Sugar: Smart Food Choices.
7. Everyday Health. (2025, January 2). Does Drinking Water Lower Blood Sugar?.
8. National Institutes of Health (NIH) | (.gov). (2025, June 2). Hemoglobin A1C - StatPearls - NCBI Bookshelf.
9. Metropolis Healthcare. (2024, December 24). Diabetes and Dehydration: How Water Intake Affects Blood ....
10. EatingWell. (2024, March 12). How Much Water Do You Need to Drink Daily When You Have ....

Frequently Asked Questions

How does dehydration affect my A1C test results?

Dehydration does not affect your A1C test result, as the test measures the average blood sugar level over the past two to three months. However, being consistently dehydrated can lead to chronically higher daily blood sugar concentrations, which will eventually be reflected in a higher A1C reading.

Can drinking water fix a dangerously high blood sugar spike?

While drinking water helps rehydrate the blood and can slightly lower the concentration of glucose, it is not an effective or immediate treatment for a significant blood sugar spike. This requires prompt medical intervention with medication, as directed by a healthcare provider.

How much water should a person with diabetes drink daily?

The recommended daily fluid intake varies based on factors like age, weight, activity level, and climate. General guidelines are around 11.5 cups (2.7 liters) for women and 15.5 cups (3.7 liters) for men, but it's best to consult a doctor for personalized advice, especially if you have other health conditions.

What are the signs of dehydration for a diabetic?

Symptoms of dehydration can include dry mouth, fatigue, headaches, dizziness, and dark urine. For diabetics, these can be confused with or compounded by high blood sugar symptoms, such as increased thirst and frequent urination.

Are other beverages besides water okay for managing blood sugar?

Opt for zero-calorie and unsweetened beverages. Herbal tea and unsweetened black coffee can be suitable in moderation. Avoid sugary drinks like soda and juice, as they cause sharp blood glucose spikes.

What is hyponatremia and why should diabetics be aware of it?

Hyponatremia is a condition caused by low blood sodium, which can result from excessive water intake. Forcing yourself to drink too much water can dilute electrolytes and lead to symptoms like nausea, headaches, and confusion. It is especially a concern for individuals with kidney or heart disease.

Does drinking water affect short-term blood glucose readings from a fingerstick monitor?

Yes, drinking water can affect short-term readings. If you are dehydrated, your blood sugar concentration may appear higher. Rehydrating can cause a slight decrease in the measured concentration, but it does not change the total amount of glucose in your blood.