Bringing high blood sugar down involves a combination of immediate actions and longer-term habits. If your fasting blood sugar is above 100 mg/dL, you’re already in the prediabetes range, and readings of 126 mg/dL or higher on two separate tests indicate diabetes. The good news is that whether you’re dealing with an occasional spike or a persistent pattern, the same core strategies work: moving your body, adjusting what and how you eat, staying hydrated, and managing sleep and stress.
What Counts as High Blood Sugar
A normal fasting blood sugar (measured after not eating overnight) is below 100 mg/dL. Between 100 and 125 mg/dL is prediabetes. At 126 mg/dL or above on two separate fasting tests, you have diabetes. A random reading of 200 mg/dL or higher at any time of day also suggests diabetes, regardless of when you last ate.
For people already managing diabetes, the American Diabetes Association recommends keeping your A1C (a three-month average of blood sugar) below 7%. Some people with otherwise good health may aim for below 6.5%, while those with other serious health conditions may have a more relaxed target. Your specific goal depends on your age, overall health, and how your body responds to treatment.
Move After Meals
Exercise is one of the fastest ways to pull sugar out of your bloodstream. When your muscles contract, they absorb glucose even without insulin, which is why a walk after dinner can visibly drop your blood sugar on a continuous monitor. Both aerobic exercise (walking, cycling, swimming) and resistance exercise (weight training, bodyweight exercises) are effective. A single session of resistance exercise can lower glucose levels for up to 24 hours afterward and reduce circulating insulin for up to 18 hours.
Timing matters. Exercising after a meal rather than before it appears to be more effective at reducing the post-meal glucose spike. You don’t need an intense gym session. Even 10 to 15 minutes of walking after eating makes a measurable difference. For lasting improvements in insulin sensitivity and overall blood sugar control, plan on at least 8 to 10 weeks of regular exercise.
Drink More Water
Dehydration directly raises blood sugar. When your body is low on water, your blood becomes more concentrated, which increases glucose levels. But the effect goes deeper than simple concentration. Dehydration triggers hormonal shifts that stimulate your liver to release more glucose into the bloodstream, compounding the problem. It also appears to reduce your cells’ ability to respond to insulin normally.
Staying well hydrated is one of the simplest and cheapest interventions for better blood sugar regulation. Plain water is the best choice. Sugary drinks, fruit juices, and sweetened beverages will obviously work against you. If your blood sugar is running high, drinking a few extra glasses of water throughout the day helps your kidneys flush out excess glucose through urine.
Restructure Your Plate
What you eat with your carbohydrates changes how fast sugar hits your blood. Adding fat to a carbohydrate-containing meal slows the glucose spike during the first one to three hours after eating, largely because fat delays stomach emptying. Protein plays a different role: it doesn’t have much immediate effect on blood sugar but helps prevent low blood sugar later by providing a slow, sustained source of glucose over three to five hours.
The practical takeaway is to avoid eating carbohydrates alone. A piece of toast with peanut butter will spike your blood sugar far less than toast by itself. Rice with chicken and vegetables is a very different metabolic event than plain rice. Pairing all three macronutrients (carbs, protein, fat) at every meal creates a flatter, more manageable blood sugar curve.
Add Fiber to Every Meal
Soluble fiber, the kind found in oats, beans, lentils, and many fruits and vegetables, forms a gel-like substance in your gut that physically slows the absorption of sugar. The effect can be dramatic. In one study, adding just 5 grams of a viscous fiber to bread reduced the glucose peak by 41%. When that same fiber was dissolved in a liquid (soup), the reduction jumped to 54%, because the fiber hydrated more completely.
Aiming for 5 to 15 grams of soluble fiber per meal is a reasonable target. Practical sources include a half-cup of cooked lentils (about 4 grams of soluble fiber), a medium apple with skin (about 1.5 grams), or a bowl of oatmeal (about 2 grams). Replacing some of the refined carbohydrates on your plate with fiber-rich foods, rather than just adding fiber on top of everything else, amplifies the benefit.
Fix Your Sleep
Poor sleep raises blood sugar even if you haven’t changed what you eat. When you’re sleep-deprived, your body ramps up cortisol production, especially in the evening when cortisol should normally be dropping. This elevated cortisol triggers your liver to push more glucose into the bloodstream and simultaneously makes your cells less responsive to insulin. The combination means higher blood sugar with less ability to clear it.
Studies on healthy volunteers show that even fragmented sleep, being woken up repeatedly, leads to decreased insulin sensitivity the next morning along with higher cortisol and increased nervous system activation. If you’ve noticed your fasting blood sugar creeping up without any dietary changes, poor sleep quality is a likely contributor. Prioritizing seven to eight hours of uninterrupted sleep can improve your numbers without any other changes.
Consider Apple Cider Vinegar
Apple cider vinegar has more clinical support than most natural remedies for blood sugar. A meta-analysis of seven controlled trials in people with type 2 diabetes found that it reduced fasting blood sugar by an average of about 22 mg/dL and lowered A1C by 1.5 percentage points. Each additional 1 mL per day of vinegar was associated with a further 1.25 mg/dL drop in fasting glucose, with greater effects seen at doses above 10 mL per day (roughly two teaspoons).
If you want to try it, dilute one to two tablespoons in a glass of water and drink it before or with a meal. Don’t take it undiluted, as the acidity can damage tooth enamel and irritate your throat. It’s not a replacement for diet and exercise, but the evidence suggests it’s a meaningful addition.
Reduce Refined Carbohydrates
This one is straightforward but worth emphasizing because it has the single largest impact. White bread, white rice, sugary cereals, pastries, soda, and fruit juice all deliver glucose rapidly into your bloodstream. Swapping these for whole grains, legumes, non-starchy vegetables, and whole fruits (with their fiber intact) reduces the total glucose load your body has to manage.
You don’t necessarily need to go low-carb. But choosing carbohydrates that come packaged with fiber, protein, or fat, essentially foods that are minimally processed, will flatten your blood sugar curve significantly. Sweet potatoes instead of white potatoes, steel-cut oats instead of instant oatmeal, whole fruit instead of fruit juice. These substitutions add up quickly.
When High Blood Sugar Becomes an Emergency
Most blood sugar spikes are manageable at home, but certain situations require immediate medical care. If your blood sugar stays at 300 mg/dL or above, you need emergency help. Other warning signs include breath that smells fruity, vomiting that prevents you from keeping food or fluids down, and difficulty breathing. These can indicate diabetic ketoacidosis, a life-threatening condition where your body starts breaking down fat too rapidly and produces dangerous levels of acid in the blood.
If you have diabetes and you’re sick or your blood sugar is above 250 mg/dL, check your levels every four to six hours and test your urine for ketones. Ketone test strips are available at most pharmacies without a prescription. A positive ketone test combined with high blood sugar means you should contact your healthcare provider right away rather than waiting it out.