Can Hydration Fix My Blood Sugar?

If you live with Type 2 diabetes, chances are, you’ve heard of supposed quick fixes to lower your blood sugar level, like drinking water.

It sounds too good to be true. And it is.

“Drinking water doesn’t directly lower your blood sugar,” says diabetes educator and registered nurse Megan Asterino-McGeean, BSN, RN, CDCES. “But staying hydrated can help prevent dehydration from making high blood sugar worse.”

Asterino-McGeean explains the benefits of hydration — and the risks of dehydration — when you’re living with this chronic disease.

Hydration and diabetes

Drinking water won’t bring down your blood sugar (glucose). But that doesn’t mean it isn’t important.

In addition to general health benefits, being well-watered helps you stay on top of diabetes by:

• Managing medication-related dehydration: “Certain Type 2 diabetes medications, like SGLT2 inhibitors, work by sending extra glucose out of your body through your pee,” explains Asterino-McGeean. “Because this process increases fluid loss, it’s especially important to stay hydrated.”
• Maintaining a healthy weight: Drinking water before and during meals helps you feel fuller, so you may eat less.
• Supporting kidney health: Diabetes can take a toll on your kidneys. Drinking more water can help them function more smoothly by helping filter out waste products like excess glucose. It can also reduce your risk of kidney stones and urinary tract infections (UTIs).

There’s another reason hydration matters: Dehydration and high blood glucose often go hand in hand.

Dehydration and high blood sugar

Dehydration and increased blood sugar can feed off of each other, each making the other worse.

“Dehydration can raise your blood sugar level because your blood is more concentrated,” says Asterino-McGeean.

To understand why this happens, it helps to know that blood sugar is measured in milligrams per deciliter (mg/dL). It’s a ratio of sugar (measured in mg) to blood or fluid (measured in dL). When there’s less water in your blood than usual, sugar takes up more space — the concentration is higher.

But drinking extra water won’t “water down” excess sugar in your blood. That’s because your body carefully balances fluid levels. If you drink more water than you need, your body simply gets rid of it through your pee.

While a lack of fluids can directly bump up your blood sugar level, high blood glucose has more of a downstream effect on dehydration.

“When you have high blood sugar, your kidneys work overtime to flush out extra sugar through your pee,” explains Asterino-McGeean. “If you’re not replenishing what you lose, high blood sugar can increase your risk of dehydration.”

In the short term, severe dehydration combined with high blood sugar levels can increase your risk of dangerous complications. These include hyperosmolar hyperglycemic state (HHS) and diabetes-related ketoacidosis (DKA).

“You’re especially at risk for HHS or DKA when you’re sick,” she warns. “That’s because your body is already under a lot of stress.”

Over time, the cycle of elevated blood sugar and dehydration can wear down your body as well, causing or worsening nerve and kidney damage.

The good news? Keeping up with your fluid intake and diabetes treatment plan can help break that cycle.

Hydration goals for diabetes

So, how much water do you actually need? There isn’t a one-size-fits-all answer.

“Each person’s needs are unique,” says Asterino-McGeean. “It’s best to discuss fluid intake goals and restrictions with your healthcare team.”

That’s because your hydration needs can change based on your:

• Age
• Activity level
• Chronic conditions
• Medications
• Metabolism

But she does recommend water as your go-to fluid source. Other hydration helpers for people with diabetes include:

• Plain tea or coffee (but be mindful of caffeine levels)
• Diet drinks, including zero-sugar sport drinks
• Diabetes-friendly foods with high-water content, like cucumbers, iceberg lettuce, celery and tomatoes

Drink up

Drinking enough water is one of the simplest ways to support your overall health when you have diabetes. But it isn’t a cure.

“Water isn’t a treatment for diabetes,” reiterates Asterino-McGeean. “Instead, think of it as a supporting actor. Your medications and management plan do the heavy lifting, while staying hydrated helps keep your overall health in check.”