If your blood sugar is running high, you can bring it down through a combination of immediate actions (hydration, movement, medication adjustments) and longer-term lifestyle changes that keep it from spiking in the first place. What works best depends on how high your levels are and whether you have diabetes. For context, the American Diabetes Association recommends a fasting blood sugar of 80 to 130 mg/dL for most adults with diabetes, and less than 180 mg/dL one to two hours after a meal.
When High Blood Sugar Is an Emergency
Not all high blood sugar readings are equally urgent, but certain thresholds and symptoms demand fast action. If your blood sugar reaches 250 mg/dL or higher, check it every four to six hours and test your urine for ketones. Ketones build up when your body starts burning fat instead of glucose for fuel, and high levels can lead to diabetic ketoacidosis, a life-threatening condition.
Call 911 or go to the emergency room if your blood sugar stays at 300 mg/dL or above, your breath smells fruity, you’re vomiting and can’t keep anything down, or you’re having trouble breathing. Other warning signs include fast deep breathing, stomach pain, muscle stiffness, and extreme fatigue. These symptoms together suggest your body’s chemistry is shifting dangerously, and you need IV fluids and insulin that only a hospital can provide.
Drink More Water
One of the simplest things you can do right now is drink water. About 80% of your blood volume is water, so when you’re dehydrated, glucose becomes more concentrated in your bloodstream, pushing readings higher even if the actual amount of sugar hasn’t changed. Rehydrating dilutes that concentration and brings your number down.
Water also supports your kidneys’ ability to filter excess glucose. When blood sugar rises above a certain point, your kidneys pull glucose out of the blood and send it into your urine. Staying well hydrated keeps that filtration process running efficiently, so more sugar leaves your body rather than circulating. Plain water is your best bet here, since juice, soda, and sports drinks add sugar back in.
Move Your Body
Physical activity is one of the most effective ways to lower blood sugar quickly. When your muscles contract during exercise, they pull glucose out of the bloodstream and use it for energy, and this happens whether or not insulin is doing its job properly. That makes exercise especially valuable for people with type 2 diabetes whose cells have become resistant to insulin.
Even a 15- to 30-minute walk after a meal can blunt a blood sugar spike. The benefits also outlast the workout itself: physical activity can keep your blood sugar lower for up to 24 hours afterward by making your cells more sensitive to insulin. Over time, regular exercise lowers your A1C, which reflects your average blood sugar over the previous two to three months. You don’t need intense gym sessions. Walking, cycling, swimming, gardening, or anything that gets you moving consistently will help.
Rethink What and When You Eat
The foods you choose have a direct, measurable effect on how high your blood sugar climbs after a meal. Refined carbohydrates (white bread, white rice, sugary cereals, pastries) break down into glucose fast and hit your bloodstream all at once. Swapping those for fiber-rich whole grains, vegetables, legumes, and protein slows digestion and produces a gentler, more gradual rise.
Pairing carbohydrates with fat, protein, or fiber also helps. Eating a piece of bread with peanut butter, for example, produces a smaller spike than eating the bread alone. Portion size matters too. You don’t necessarily need to eliminate carbs, but cutting a serving in half or replacing part of the starch on your plate with non-starchy vegetables can make a significant difference in your post-meal numbers.
One home remedy with some clinical support is vinegar. A meta-analysis in Diabetes Research and Clinical Practice found that consuming vinegar (often as a tablespoon of apple cider vinegar diluted in water before a meal) significantly reduced both post-meal blood sugar and insulin levels compared to controls. The effect is modest, not a replacement for medication, but it’s a low-risk addition to your routine if you tolerate it.
Get Enough Sleep
Sleep loss raises blood sugar even if nothing else in your routine changes. A study from Columbia University found that shortening sleep by just 90 minutes a night for six weeks increased insulin resistance by nearly 15% in women who normally slept enough. Postmenopausal women in the study saw insulin resistance jump by more than 20%. Insulin resistance means your cells don’t respond to insulin as well, so glucose stays in your bloodstream longer.
The participants in that study were only sleeping about six hours a night, which is common for many adults. If you’re consistently getting less than seven hours, improving your sleep may lower your blood sugar without any other intervention. Keeping a consistent bedtime, limiting screens before bed, and avoiding caffeine in the afternoon are practical starting points.
Manage Your Stress
When you’re stressed, your body releases cortisol, a hormone that tells your liver to produce and release more glucose into your bloodstream. This is a survival mechanism designed to give your muscles quick fuel during a threat. The problem is that chronic stress (work pressure, financial worry, caregiving demands) keeps cortisol elevated, which keeps your liver pumping out glucose even when you haven’t eaten anything.
Cortisol also works against insulin by stimulating enzymes that drive glucose production. Over time, this creates a cycle where stress pushes blood sugar up, and elevated blood sugar itself becomes a source of anxiety. Strategies that reliably lower cortisol include deep breathing exercises, meditation, regular physical activity, and spending time outdoors. Even 10 minutes of slow, focused breathing can interrupt the cortisol response and bring your levels down.
How Medications Help
If lifestyle changes alone aren’t enough, several classes of medication can lower blood sugar through different mechanisms. The most commonly prescribed is metformin, which reduces the amount of glucose your liver produces and makes your muscle tissue more responsive to insulin. Other medications stimulate your pancreas to release more insulin, slow down carbohydrate digestion in your intestines, or cause your kidneys to excrete more glucose through urine.
One newer class works by keeping a natural hormone called GLP-1 active in your body longer. GLP-1 helps lower blood sugar only when it’s elevated, which reduces the risk of your levels dropping too low. Another class blocks your kidneys from reabsorbing glucose, so excess sugar leaves your body when you urinate. Your prescriber will choose a medication (or combination) based on whether your body doesn’t make enough insulin, doesn’t use it efficiently, or both.
If you take insulin, knowing how to use correction doses is important for bringing down a high reading. The timing and amount depend on the type of insulin you use and your individual sensitivity, so work with your care team to establish a correction plan you can follow at home.
Track Your Patterns
Random blood sugar checks tell you what’s happening in the moment, but patterns tell you why. Checking before and one to two hours after meals helps you identify which foods cause the biggest spikes. Logging your readings alongside what you ate, how much you moved, and how you slept lets you spot connections that aren’t obvious otherwise. Many people discover that a specific breakfast food, a stressful weekly meeting, or a poor night’s sleep reliably pushes their numbers up.
Continuous glucose monitors, which sit on your skin and take readings every few minutes, make pattern-spotting much easier. But even a basic finger-stick meter and a notebook can reveal a lot if you use them consistently for a week or two. The goal isn’t perfection on every reading. It’s understanding what moves the needle for your body so you can make targeted changes instead of guessing.