How to Lower Blood Sugar Immediately

4 ways to quickly get your glucose down when it's dangerously high

High blood sugar (hyperglycemia) in people with diabetes can be lowered quickly with an insulin injection. For people who are not prescribed insulin, exercise is your best option for bringing down high blood sugar levels.

Other ways to reduce blood sugar levels quickly including taking missed medication, drinking lots of water, and using stress-management tools.

If you have type 1 or type 2 diabetes, keeping blood sugar in a normal range is always important. At a certain point, however, lowering blood sugar becomes immediately necessary to avoid potentially life-threatening complications.

This article discusses the four best ways to lower your blood sugar quickly. It also explains the warning signs of dangerously high blood sugar and when you should contact your healthcare provider.

How to Lower Blood Sugar Immediately - Illustration by Theresa Chiechi

Verywell / Theresa Chiechi

Take Insulin

Taking rapid-acting insulin is the quickest way to lower your blood sugar and is the preferred method for treating hyperglycemia.

In people with type 1 diabetes, taking rapid-acting insulin or receiving a correction dose through your insulin pump is necessary.

Some people with type 2 diabetes may also require intermittent or continuous insulin therapy.  

Subcutaneous (under the skin) insulin injection provides the quickest response because blood flow at the injection site accelerates insulin absorption.

Injecting it into the abdomen, arm, or deltoid is the most effective due to increased blood flow in these locations compared to other body areas like the buttocks and thigh.

However, be aware that factors like smoking, obesity, and low physical activity can decrease a person’s subcutaneous blood flow and slow down the absorption rate.

Intramuscular injection may be more effective in rare cases of DKA or dehydration, since the absorption rate is even higher. The effectiveness, though, can be a drawback in cases of hyperglycemia because the insulin may be absorbed too readily and result in a drastic drop in blood sugar (hypoglycemia).

Inhaled Insulin

Inhalable insulin is a powdered form of rapid-acting insulin that can be delivered to the lungs with an inhaler. Clinical trials have shown that although it is not superior to injectable insulin, it does offer similar benefits in reducing blood sugar. It is, however, costlier than injectable insulin. It is also unsuitable for patients with asthma, active lung cancer, or chronic obstructive pulmonary disease (COPD). 

Take Missed Medication

If you use long-acting insulin or other diabetes medication and your blood sugar is high, check to make sure you took your medication.

If you have type 2 diabetes, your healthcare provider may prescribe medication to help keep your blood sugar within the normal range. Missing these medications can result in hyperglycemia. 

Medications used to help with diabetes include:

  • Symlin (pramlintide injection): It delays the digestive process and reduces glucagon secretion (a digestive hormone that raises blood sugar).
  • Precose (acarbose) and other alpha-glucosidase inhibitors: They lower blood sugar by supporting your body’s ability to break down starchy foods and sugar.
  • Metformin (biguanide): It increases your body’s insulin sensitivity by reducing the amount of sugar that is made by your liver and absorbed by the large intestine.

If you miss a dose of your diabetes medication, take it as soon as you remember, but don't double-up by taking your missed medication too closely to your next scheduled dose. This can cause adverse reactions.

When in doubt, consult the guide on the packaging of the medication or look for its Food and Drug Administration medication guide. If you miss several doses, contact your practitioner to discuss the best course of action.


Physical activity is the fastest way to lower your blood sugar naturally. Exercise lowers insulin resistance and improves the body's ability to convert glucose into energy.

During muscle contractions, your cells take up glucose for energy and use it whether insulin is available or not, resulting in lower blood sugar. This effect lasts for 24 hours or more after you’ve exercised.

There is no perfect formula for exercising to reduce your blood sugar. Everyone responds differently to exercise. However, it’s generally understood that you’ll need to get your heart rate up and that longer durations of physical activity require more glucose for energy, which lowers your blood sugar.

To better understand how your body responds to exercise, do regular blood sugar checks before and after working out. Record any differences in your blood glucose in between activities to see which ones are the most effective for lowering your blood sugar (such as fast-paced walking, water exercising, bicycling, etc.).

When to Avoid Exercise

People with blood sugar levels above 240 mg/dL should check their urine for ketones before engaging in physical activity. If ketones are present, do not exercise. Ketones are the result of stored fat being broken down for energy. Your liver starts breaking down fat when there’s not enough insulin in your bloodstream to absorb blood sugar into cells. When too many ketones are quickly produced, they can cause DKA. In this state, ketones may actually make your blood sugar level go even higher and you may need intravenous fluids to rebalance.

Drink Water

Water is a critical component of diabetes management because it helps your body excrete glucose. Therefore, staying sufficiently hydrated is key to maintaining normal blood sugar levels. In hyperglycemia, you need more water (or unsweetened fluids) than usual to help your kidneys flush the excess sugar from your body through urination.

Not drinking enough water leads to dehydration and can force your body to draw water from other sources like saliva and tears. Your body will also excrete sugar in the urine, leading to further dehydration. 

The Centers for Disease Control and Prevention says the daily fluid intake recommendation varies by factors such as age, sex, pregnancy, and breastfeeding status.

So how much water should you drink? It is generally accepted that most people need about four to six cups of water each day.

If you sweat during work or exercise, that fluid needs to be replaced so you should drink more. However, if you take medications that cause fluid retention, you may need less.

Ask your healthcare provider about the right amount of water needed to keep your blood sugar levels in the normal range.

Risks of Very High Blood Sugar

Hyperglycemia can be dangerous, especially for people with type 1 diabetes. It can lead to a deadly condition known as diabetic ketoacidosis (DKA).

The risk for DKA starts at 240 mg/dL, but is more likely in much higher blood sugar levels.

Signs of DKA include nausea or vomiting, fruity-smelling breath, extreme thirst, and frequent urination. You can test for ketones at home using a urine test. If you have high ketones, call your doctor or go to the emergency room.

In people with type 2 diabetes, high blood sugar (over 600 mg/dL) can cause hyperglycemic hyperosmolar syndrome (HHS). HHS is potentially fatal and can occur after several days or weeks of sustained high blood sugar.

In people with diabetes, high blood sugar is caused by things like:

  • Eating too many carbohydrates
  • Not getting enough physical activity
  • Stress from an illness or infection
  • Taking a corticosteroid, like prednisone
  • Skipping or not taking enough glucose-lowering medication

When to Contact Your Healthcare Provider

If you have two blood sugar readings of 300 mg/dL or more or have blood sugar above your target range (anything above 180 mg/dL) for more than a week, seek immediate medical help.

Hyperglycemia can turn into a medical emergency like DKA and HHS that requires immediate intervention by your practitioner or a local emergency department.

Signs of hyperglycemia include:

  • Confusion
  • Excessive thirst
  • Frequent urination
  • Ketones in your urine (diagnosed using an at-home urine dipstick test)
  • Stomach pain, nausea, or vomiting
  • Shortness of breath
  • Fruity breath

Signs that it’s time to call your healthcare provider include:

  • Consistently high blood sugar readings
  • Frequent urination
  • High levels of sugar in the urine (diagnosed using at-home glucose dipstick test)
  • Increased thirst

A Word From Verywell 

While it’s important to know the signs and what to do if your blood sugar is too high, it is even more crucial to develop a daily diabetes management plan that keeps glucose in a normal range in the first place.

Mild hyperglycemia does not pose an immediate threat, but chronic high blood sugar can lead to long-term diabetic complications such as vision problems, heart disease, kidney disease, and nerve damage.

Frequently Asked Questions

  • What foods can lower blood sugar quickly?

    There are none. But if your blood sugar is high, stick with foods that are less likely to raise your blood sugar, such as non-starchy vegetables, meat, cheese, nuts, or avocados. Avoid carbohydrates like bread, potatoes, rice, and fruit.

  • What can I drink to lower blood sugar quickly?

    Water is the best choice. Excess sugar in the blood is filtered through the kidneys and excreted through urine, and keeping hydrated can help your body expel that sugar faster. Avoid juice and sweetened beverages.

  • How long does it take for blood sugar to go down?

    It depends on your level and what you're doing to lower it. For example, rapid-acting insulin starts to work in 15 minutes and continues to lower blood sugar for up to four hours. Oral diabetes medication can take several hours or even days to lower blood sugar.

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Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Michelle Pugle
Michelle Pugle, BA, MA, is an expert health writer with nearly a decade of contributing accurate and accessible health news and information to authority websites and print magazines. Her work focuses on lifestyle management, chronic illness, and mental health. Michelle is the author of Ana, Mia & Me: A Memoir From an Anorexic Teen Mind.