How To Lower Blood Sugar Immediately

If you have high blood sugar, a condition also known as hyperglycemia, there’s too much sugar in your blood and not enough insulin in your body to lower it. In people with diabetes, hyperglycemia can be caused by things like eating too many carbohydrates, lack of physical activity, stress from an illness or infection, nondiabetes medications (such as steroids for another condition), or skipping or not taking enough glucose-lowering medication.

Hyperglycemia requires immediate treatment to prevent serious complications, including nerve, tissue, and organ damage; diabetic ketoacidosis (DKA); and hyperglycemic hyperosmolar syndrome (HHS). While taking rapid-acting insulin is the quickest way to lower your blood sugar, there are other ways like exercising and staying hydrated that can help. In cases of an emergency, contact your healthcare provider immediately. 

How to Lower Blood Sugar Immediately - Illustration by Theresa Chiechi

Verywell / Theresa Chiechi

Take Insulin

Taking 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 dose through your automatic insulin pump is necessary. Some 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 not suitable for patients who have asthma, active lung cancer, or chronic obstructive pulmonary disease (COPD). 


Physical activity can help lower your blood sugar in the short and long term. While exercising, your body is better able to use insulin to take up glucose and use it for energy. During muscle contractions, your cells take up glucose for energy and use it whether insulin is available or not, resulting in a 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 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.

Take Missed Medication

If you have diabetes, your healthcare provider may prescribe insulin 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 works by delaying the digestive process and reducing 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.

When to Contact Your Healthcare Provider

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

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 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 prevents hyperglycemia from ever occurring. When your body doesn’t have to endure blood sugar spikes, you can lower your chances of having serious complications. However, even the best laid plans can be disrupted by things like forgetting to take a dose of your medication. When you have high blood sugar, act immediately to lower it by taking insulin, exercising, drinking water, and responding appropriately to missed medication. When in doubt, talk to your healthcare provider.

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14 Sources
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