How to Prevent Blood Sugar Spikes

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Blood sugar spikes are sharp rises in blood sugar levels. They can happen due to a variety of factors, but often occur when you eat too many simple carbohydrates. In this article, we share possible reasons for blood sugar spikes, as well as what you can do to manage blood sugar levels and prevent blood sugar spikes from occurring.

Blood sugar spikes are often brought on when eating too much food containing carbohydrates. When you eat food containing carbohydrates, your body breaks down the carbohydrates into a simple sugar called glucose.

Blood Sugar Management - Illustration by Laura Porter

Verywell / Laura Porter

Glucose then enters your bloodstream. When the amount of glucose in your blood starts to rise, it sends a signal to your pancreas to release a hormone called insulin

Insulin’s job is to act like a key to unlock the doors of different cells in your body. This allows glucose to leave the bloodstream and enter the cells to be used for energy, or be stored for later use. Without insulin, glucose stays in the bloodstream, causing blood glucose (or blood sugar) levels to rise too high. This can lead to serious health problems.

In diabetes, sometimes there isn’t enough insulin or it isn’t working properly. Because of this, it’s very important for people with diabetes to regularly monitor their blood sugar levels, making sure they are in a safe range.

Illustrated human body with arrows outlining common symptoms of hyperglycemia. Text on image reads: Hyperglycemia: Common Symptoms: fatigue; blurry vision; excessive thirst; fruity breath; increased hunger; nausea and vomiting; increased urination.


Symptoms of a Blood Sugar Spike

The longer your blood sugar levels stay elevated, the more symptoms you are likely to develop, and the more damage is being done to your body. While there are some hallmark symptoms of high blood sugar levels (hyperglycemia), they can vary from person to person.

Learning to recognize your individual symptoms of high blood sugar early on can help minimize any damage to your body and keep your diabetes in control.

Common symptoms of high blood sugar include:

  • Frequent urination
  • Increased thirst
  • Constant hunger
  • Blurry vision
  • Fatigue
  • Headache
  • Numbness or tingling in your hands or feet

If you are experiencing any of these symptoms, get your blood sugar level tested. It can be as simple as a small finger poke but can go a long way in helping you manage your blood sugar levels. 

If you do not have diabetes and are experiencing any of these symptoms, seek medical attention as soon as you can to get your blood sugar levels tested. Early identification of high blood sugar levels and diabetes can save your life.

Diabetic Ketoacidosis

If your blood sugar levels remain high for too long, glucose will remain trapped in your bloodstream, leaving your cells starved for energy.

When there is not enough of your body's preferred energy source of glucose to be used for energy, your cells begin to use fat for fuel. When your cells use fat for fuel instead of glucose, it creates a byproduct called ketones.

In people with diabetes who don't make any insulin or whose insulin isn't working properly, ketone levels can rapidly rise to dangerous levels. When ketone levels get too high in people with diabetes, the blood can become overly acidic, and they can develop diabetic ketoacidosis (DKA).

Diabetic ketoacidosis is different from ketosis, the state aimed for by people following the ketogenic diet. DKA is a medical emergency and can result in diabetic coma or death.

Call 911 or seek medical attention immediately if you experience any signs or symptoms of DKA, such as:

  • Fruity smelling breath
  • Nausea and vomiting
  • Severe dry mouth
  • Shortness of breath
  • Weakness
  • Abdominal pain
  • Confusion
  • Passing out, or coma

Causes and Risk Factors

As your body goes between fed and unfed states throughout the day, your blood sugar levels will naturally fluctuate up and down. In someone without diabetes, blood sugar levels are regulated by insulin and stored glycogen to stay within normal ranges.

If you have diabetes, you are at a higher risk of having a blood sugar spike than people without diabetes. Eating foods high in simple carbohydrates, like desserts, sugar-sweetened beverages, and refined-grain pasta and bread, are the main cause of blood sugar spikes.

However, there are additional causes for high blood sugar levels, such as:

  • Eating more than planned
  • Exercising less than planned
  • Not taking enough diabetes medication (oral or injectable) or needing changes to your medication dosage
  • Illness or infection
  • Having an injury or recent surgery
  • Stress
  • Taking certain medications, such as steroids
  • Over-treating low blood sugar levels
  • Dehydration
  • Dawn phenomenon: This is a natural surge in blood sugar early in the morning. It can be higher in people with diabetes who have insulin resistance.
  • Somogyi effect: This is high early morning blood sugar levels caused by a rebound effect from low blood sugar levels in the middle of the night and your body triggering a release of hormones to raise blood sugar levels.

Blood Sugar Management

Self-management of blood sugar levels is a key component of diabetes care. Being able to identify high and low blood sugar levels and knowing how to treat them is critical if you have diabetes. Below are some tips on how you can properly manage your blood sugar levels.

Proper Hydration

Staying hydrated is important even if you don’t have diabetes. Water makes up most of the body and plays a role in many different body functions. From digestion and absorption of nutrients to lubricating joints and maintaining your body temperature, water is vital to life.

In people with diabetes, dehydration can cause blood sugar levels to become more concentrated, spiking blood sugar levels.

Drinking water throughout the day will provide you with most of your daily fluid needs. Water from foods, such as fruits and vegetables, also adds to your daily water intake. Opt for water over sugar-sweetened beverages, such as soft drinks, flavored coffee beverages, juice, sports drinks, sweet tea, and others.

Tips for drinking more water include:

  • Keep a water bottle nearby and refill it throughout the day.
  • Make “infused” water by adding slices of fresh fruit, vegetables, or herbs to your water.
  • Drink sparkling water with a splash of 100% fruit juice.
  • Ask for water when dining out.
  • Keep a pitcher of water in the refrigerator to always have cold water to drink.

Meal Timing

When you eat can be just as important as what you eat when managing blood sugar levels. Being consistent with meal timing can help prevent blood sugar swings. Have a regular eating schedule where you eat the same amount of meals and snacks around the same time each day. 

This might look like three regular meals with two to three snacks in between, or it might be five to six smaller meals throughout the day. Choose what works best for you and stick with it. 

Relaxation Techniques

Circulating stress hormones can raise blood sugar levels, so learning techniques to help you relax and de-stress may help reduce blood sugar levels. What is relaxing for one person may make someone else more stressed. Explore different techniques and methods to help manage your stress. Find what works for you.

Some examples include:

  • Meditation
  • Deep breathing
  • Progressive muscle relaxation (alternating tension and relaxation in the major muscle groups)
  • Journal writing
  • Going for a walk
  • Reading a book
  • Yoga
  • Listening to calming music
  • Taking a warm bath

Better Sleep

Getting enough quality sleep each night can help reduce stress hormones and reduce the risk of having obesity. Aim for seven to nine hours of sleep each night while having regular sleep and wake times–which will help to regulate your circadian rhythm.

Other tips for getting better sleep include:

  • Put away electronics, such as cell phones and TV, at least an hour before bedtime.
  • Limit daytime naps.
  • Keep a calm and restful sleeping environment.
  • Participate in physical activity throughout the day.
  • Avoid caffeine late in the day.

Physical Activity

Physical activity can increase insulin sensitivity, helping it work better to decrease blood sugar levels. Aim for 150 minutes of moderate physical activity per week.

If you haven’t exercised in a while, start small. Try to fit in 15 to 20 minutes of exercise each day, or break it up into 10 minutes three times a day. Move your body in ways you enjoy, choosing activities that you like and can stick to.


Medication can help you manage your diabetes and keep your blood sugar levels from spiking. There are two main types of diabetes medications: oral (pills) and injectable.

What medication you take will depend on various factors, such as the type of diabetes you have, your personal health history, current diabetes management, and other medications you may also be taking. Try not to skip any doses of your medication and never stop taking it without consulting your doctor first.

Preventing Blood Sugar Spikes

There are additional ways to prevent blood sugar spikes.

Monitor blood sugar levels. The first step in preventing blood sugar spikes is knowing what your blood sugar levels are in the first place. Especially if you take a medication that directly affects your blood sugar level, such as insulin, you should be checking your blood sugar level often. 

A good starting place is checking your blood sugar level every morning before you eat—this is called a fasting blood sugar level. This once-per-day testing might be sufficient for some people with type 2 diabetes. However, others may need to check their blood sugar level up to 10 times daily.

Choose whole grains. Compared to refined grains, whole grains contain the entire grain, including the fibrous outer layer called the bran and the nutrient-rich inner core called the germ. Choosing to eat whole grains ensures you get the most nutrients out of your grains.

Because fiber isn’t absorbed and broken down in the body like other carbohydrates, it doesn’t result in a big blood sugar spike.

Balance meals with fat and protein. You can help prevent blood sugar spikes by balancing your meals with fat and protein in addition to carbohydrates.

Meals that contain only carbohydrates are easily broken down into glucose and sent into your bloodstream. Fat and protein help slow down the digestion of carbohydrates and, in turn, their absorption into the bloodstream.


Blood sugar spikes are caused by a variety of factors, a main one being carbohydrates in the food and drinks you consume. Common symptoms of high blood sugar include increased thirst, frequent urination, constant hunger, and blurry vision.

You can better manage blood sugar levels and prevent spikes in blood sugar by monitoring blood sugar levels, drinking water instead of sugary beverages, eating consistent meals and snacks, getting adequate sleep, managing stress, regularly exercising, and following a balanced diet. 

A Word From Verywell

It is normal and natural for blood sugar levels to fluctuate throughout the day. However, blood sugar spikes are higher than normal rises. Knowing your individual symptoms of high blood sugar levels and regularly monitoring your blood sugar levels if you have diabetes can help you identify blood sugar spikes.

Managing your diabetes at home is a critical part of preventing blood sugar spikes. Also work with your healthcare team to create a diabetes treatment plan that works for you.

Frequently Asked Questions

  • What is considered a spike in blood sugar?

    A blood sugar spike is a sharp, quick rise in blood sugar levels, followed by a similar decline. There is no consensus on the exact blood sugar level that is considered a spike, as it will vary depending on the individual.

    However, any reading that is noticeably above your usual blood sugar level range would be considered a spike for you.

  • How long can blood sugar spikes last?

    The length of blood sugar spikes can vary greatly from person to person and even meal to meal. In general, blood sugar spikes tend to occur within one to two hours after beginning a meal, depending on what you ate, and can last anywhere from several minutes to several hours.

  • What causes blood sugar to rise without eating?

    While the main cause of blood sugar spikes tends to be carbohydrates you have consumed, there are other non-food factors that can cause high blood glucose levels.

    These include not taking enough medication (oral or injectable), needing changes to your medication dosage, illness, infection, having an injury or recent surgery, stress, taking certain medications, such as steroids, dehydration, the Somogyi effect, and the dawn phenomenon.

  • Are there ways to manage high blood sugar in the morning?

    The first step in managing high morning blood sugar levels is determining what is causing them. Checking your blood sugar level at bedtime, in the middle of the night, and first thing in the morning can help you identify trends in your blood glucose levels leading up to the morning high.

    Adjusting your medication (after consulting with your healthcare provider), changing the amount or type of food eaten at dinner or bedtime snacks, or going on a walk after dinner can all make a difference in morning blood sugar levels.

5 Sources
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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  2. Depner CM, Stothard ER, Wright KP Jr. Metabolic consequences of sleep and circadian disorders. Curr Diab Rep. 2014;14(7):507. doi:10.1007/s11892-014-0507-z

  3. Centers for Disease Control and Prevention. Diabetes: get active.

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By Brittany Poulson, MDA, RDN, CD, CDCES
Brittany Poulson, MDA, RDN, CDCES, is a registered dietitian and certified diabetes care and education specialist.