Treating high blood sugar depends on whether you need to bring it down right now or manage it over time. For most adults with diabetes, the goal is a pre-meal blood sugar between 80 and 130 mg/dL and a reading below 180 mg/dL one to two hours after eating. If your numbers are running above those targets, a combination of hydration, movement, food choices, sleep, and (for many people) medication can bring them back in line.
Bring It Down Right Now
When your blood sugar is elevated but not in emergency territory, two things help quickly: water and movement. Drinking water helps your kidneys flush excess glucose through urine. There’s no magic amount, but steady sipping over the next hour or two is more effective than forcing a large volume at once. Dehydration makes high blood sugar worse, so if you’ve been running high, you’re likely already behind on fluids.
Light physical activity, like a 15- to 20-minute walk, pulls glucose out of your bloodstream and into your muscles for energy. One important caveat: if your blood sugar is above 270 mg/dL, check your urine for ketones before exercising. Ketones are acids your body produces when it burns fat instead of sugar, and exercising with high ketone levels can push you toward a dangerous condition called ketoacidosis. If ketones are present, skip the walk and focus on hydration and your prescribed insulin instead.
If you use rapid-acting insulin, a correction dose based on the plan your prescriber gave you is the fastest pharmacological option. Most correction plans use a ratio, something like one unit for every 50 mg/dL above your target. Don’t stack doses. Wait at least two to three hours after a correction before deciding whether you need more.
Build Meals That Prevent Spikes
What you eat is the single biggest lever for day-to-day blood sugar control. Carbohydrates raise blood sugar; protein and fat raise it much less. That doesn’t mean you need to eliminate carbs, but pairing them with fiber, protein, or fat slows digestion and flattens the glucose curve.
Fiber is especially powerful. Your body doesn’t break it down the way it breaks down other carbohydrates, so it doesn’t cause the same spike. The Dietary Guidelines for Americans recommend 22 to 34 grams of fiber per day depending on age and sex, but most people fall well short. Good sources of soluble fiber, the type most directly linked to blood sugar control, include oats, black beans, lima beans, apples, avocados, and Brussels sprouts. Insoluble fiber from whole wheat, bran, nuts, and seeds supports digestion more broadly.
A practical approach: fill half your plate with non-starchy vegetables, a quarter with protein, and a quarter with a complex carbohydrate like brown rice, quinoa, or sweet potato. Eating your vegetables and protein before your carbohydrates within the same meal has been shown to produce a smaller glucose spike than eating the carbs first.
How Sleep Affects Blood Sugar
Poor sleep makes your cells resist insulin, which means glucose stays in your bloodstream longer. The size of this effect is striking. Limiting sleep to about five hours a night for five consecutive nights reduced insulin sensitivity by 21% in one study. Restricting sleep to four or four and a half hours produced drops of 16% to 29% across multiple trials. Even a single night of sleep deprivation cut insulin sensitivity by roughly 21%.
This means that if you’re doing everything else right, consistently sleeping fewer than six hours can undermine your efforts in a measurable way. Prioritizing seven to eight hours of sleep isn’t a soft lifestyle suggestion. It’s one of the most effective things you can do for glucose control, on par with dietary changes for some people.
Exercise Beyond the Quick Walk
Regular physical activity improves how well your cells respond to insulin for hours and even days after a workout. Both aerobic exercise (walking, swimming, cycling) and resistance training (weights, bodyweight exercises, resistance bands) help, and combining the two works better than either alone. Aim for at least 150 minutes per week of moderate activity, spread across most days rather than crammed into one or two sessions.
Timing matters for blood sugar specifically. A 10- to 15-minute walk after a meal can blunt the post-meal spike more effectively than exercising at a random time of day. If you’re checking your blood sugar before exercise, keep these Mayo Clinic guidelines in mind: below 90 mg/dL may be too low to exercise safely, and above 270 mg/dL requires a ketone check before you start. Stop exercising if your blood sugar drops to 70 mg/dL or lower.
How Medications Help
When lifestyle changes aren’t enough to reach your targets, medication fills the gap. The most commonly prescribed first-line option works by reducing how much glucose your liver releases and improving your cells’ sensitivity to insulin. It’s typically started at a low dose and gradually increased over weeks to minimize stomach-related side effects like nausea or diarrhea.
A newer class of medications mimics a gut hormone that triggers insulin release only when blood sugar is high, slows stomach emptying so food is absorbed more gradually, and reduces appetite. These are given as weekly or daily injections and have become popular partly because they also promote weight loss, which independently improves blood sugar control.
Another class works on the kidneys, causing them to excrete excess glucose in your urine rather than reabsorbing it back into the bloodstream. These medications lower blood sugar regardless of insulin levels and also have cardiovascular and kidney-protective benefits. Your prescriber will choose among these options, or combine them, based on your numbers, other health conditions, and how your body responds.
Track Your Numbers Effectively
You can’t manage what you don’t measure. Traditional finger-stick meters give you a snapshot, but continuous glucose monitors (CGMs) provide a rolling picture of your blood sugar throughout the day and night. If you use a CGM, the key metric to watch is “time in range,” which is the percentage of the day your glucose stays between 70 and 180 mg/dL. The recommended target for most adults with type 1 or type 2 diabetes is more than 70% of the day in that range.
Even without a CGM, strategic finger-stick testing reveals patterns. Checking before meals and one to two hours after gives you the information you need to see which foods, activities, and routines are helping and which are driving spikes. Keep a simple log for a week or two, and the patterns usually become obvious.
Stress and Blood Sugar
When you’re stressed, your body releases hormones that tell the liver to dump stored glucose into the bloodstream for quick energy. This was useful when stress meant running from a predator, but for modern chronic stress it just keeps blood sugar elevated. Illness, emotional distress, and physical pain all trigger the same response. If you notice your numbers climbing during stressful periods despite no changes in diet or activity, this is likely why. Regular stress-reduction practices, whether that’s deep breathing, meditation, time outdoors, or simply boundaries on overwork, can have a real effect on your readings.
Warning Signs That Need Emergency Care
Most high blood sugar episodes are manageable at home, but certain signs point to a medical emergency. If your blood sugar stays at or above 300 mg/dL and won’t come down, your breath smells fruity, you’re vomiting and can’t keep food or liquids down, or you’re having trouble breathing, these are signs of diabetic ketoacidosis. This is a life-threatening condition that requires emergency treatment with IV fluids and insulin in a hospital setting.
If your blood sugar is 250 mg/dL or higher and you’re feeling ill, check your blood sugar every four to six hours and test your urine for ketones. Elevated ketones alongside persistent high blood sugar means you should head to the emergency room or call 911 rather than trying to manage it on your own.