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How to lower your blood sugar quickly: 3 ways 

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Take medicationExerciseDrink waterWhen to contact a doctorSummary
The most effective way to lower blood sugar (blood glucose) levels quickly is by taking rapid-acting insulin. Exercise, like a brisk walk, is the next fastest option.
Medically reviewed by Lauren Castiello, MS, AGNP-C
Written by D. M. Pollock
Updated on

High blood sugar (hyperglycemia) has many causes, including illness, stress, eating large meals, and taking too little insulin. Symptoms include feeling very thirsty and urinating often.

According to the Centers for Disease Control and Prevention (CDC), target blood sugar levels for people with diabetes are:

  • 80–130 milligrams per deciliter (mg/dL) before a meal
  • less than 180 mg/dL 2 hours after the start of a meal

The quickest ways to reduce blood sugar levels are by taking rapid-acting insulin, doing light exercise, or drinking lots of water.

A blood sugar reading of over 240 mg/dL may be dangerous. If your reading reaches this amount, check your urine for ketones. Talk with a doctor or go to the hospital if your ketone levels are high, as this can indicate a medical emergency called diabetic ketoacidosis (DKA).

If you have ketones in your urine, avoid exercise, as this might increase your blood sugar levels further.

1. Take rapid-acting insulin

An insulin injection that lowers blood sugar fast
Maskot/Getty Images

Administering rapid-acting insulin increases your insulin levels. This can curb dangerous increases in blood sugar and, if done correctly, can improve blood sugar management. Always follow your healthcare professional’s instructions when taking insulin.

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Rapid-acting insulin is most effective when taken 15–20 minutes before a meal. It’s important to check your blood sugar levels frequently after taking insulin to ensure the medication is working.

The University of California says that, on average, one unit of insulin is enough to drop your blood sugar by 50 mg/dL. But this can vary from 30–100 mg/dL depending on individual insulin sensitivities.

Examples of insulin medication include the following:

  • Rapid-acting insulin — works about 15 minutes after the injection and lasts 2–4 hours. Types include:
  • Short-acting (regular) insulin — works within 30 minutes of the injection and lasts 3–6 hours. Types include:
  • Intermediate-acting insulin — works 2–4 hours after the injection and lasts 12–18 hours. Types include:
  • Long-acting insulin — works within several hours and can last up to 24 hours. Types include:
  • Ultra long-acting insulin — works within 6 hours and lasts 36 hours or longer. An example is glargine U-300 (Toujeo).

When calculating how much insulin to take and when to take it, it’s important to follow the instructions given by your doctor. If you’re unsure, it’s best to call a doctor for advice.

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2. Try to exercise

The American Diabetes Association says exercise is an effective way to reduce high blood sugar. Exercise increases your insulin sensitivity, meaning your muscle cells can use your body’s insulin to produce energy and use up the glucose in your blood.

As your muscles contract, they use the glucose in your blood, whether insulin is present or not. These effects can last up to 24 hours after a workout. Light exercise that elevates your heart rate is the most effective.

However, exercise can also lead to hypoglycemia (low blood sugar) if you’re already taking insulin. It’s important to follow a doctor’s advice about how much exercise is helpful to avoid over-exercising and developing hypoglycemia.

If your blood sugar exceeds 240 mg/dL, healthcare professionals suggest avoiding exercise, as it may increase your blood sugar levels. Instead, check your urine for ketones and speak with a healthcare professional if ketones are present.

3. Drink water

When your blood sugar runs high, your body will try to flush out the excess glucose. This is why many people feel an urgent need to urinate when hyperglycemic. Keeping yourself hydrated can help the body flush out excess glucose through your urine.

Drinking water may be especially effective in people with type 1 diabetes when taken alongside insulin.

Contacting a doctor

Having diabetes, especially type 1 diabetes, means you may be at risk of developing DKA. This happens when your body’s insulin levels are so low that no blood sugar can enter your body’s cells for use as energy. This means your liver begins to burn your fat reserves for energy, which produces ketones.

High blood sugar can also lead to hyperosmolar hyperglycemic syndrome (HHS), a condition that can develop due to complications with type 2 diabetes.

DKA and HHS can develop into medical emergencies if left untreated.

DKA is more frequent in people with type 1 diabetes. If you experience the following symptoms, it’s important to seek medical attention:

  • ketones in your urine, which you can check using a urine dipstick
  • intense thirst
  • nausea or vomiting
  • frequent urination
  • dizziness and confusion
  • rapid weight loss, in the case of uncontrolled high blood sugar

If you consistently find your blood sugar level high, it’s important to check with a doctor. Diabetes medication can help you manage your symptoms and prevent complications.

If you’re finding it difficult to manage your diabetes, it may help to speak with a specialist endocrinologist. You can find a list of certified endocrinologists on the American Association of Clinical Endocrinologists website. 


Correctly administering insulin, exercising, and keeping well hydrated can reduce your blood sugar levels quickly. These are the methods best supported by research.

However, if you experience symptoms of DKA or HHS, it’s important to seek emergency medical attention. Regularly monitoring your blood sugar can help prevent future episodes of hyperglycemia.

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