• Nov 2023(updated on Feb 2024)

What is a glucose spike? Definition, causes and management

What is a glucose spike? Definition, causes and management
  • Glucose spikes, also known as blood sugar spikes, occur when you have more glucose in your bloodstream than your cells can take in for energy.  
  • Glucose spikes can negatively impact your sleep, energy, mood, and focus, which is why managing spikes day-to-day also has benefits.
  • Consistent glucose spikes, sometimes followed by crashes, can also lead to health complications such as insulin resistance, type 2 diabetes, and heart disease.  
  • You can avoid or lessen glucose spikes by implementing various lifestyle habits. Continuous glucose monitors like Lingo can help you monitor your spikes and establish healthy habits to keep your blood sugar steady.
Glucose spikes: definition, causes and management

After you eat, your body breaks down the food or drink to be used for energy or stored for later use. Of the three macronutrients — carbohydrates, protein, and fat — carbohydrates are the quickest to digest. (1,2) Carbohydrates are converted into glucose, which is one of your body’s main sources of energy.

Glucose circulates via the bloodstream to get into cells where it’s used for energy. Any glucose not being used as an immediate source of fuel is shuttled to the liver, muscles, or fat cells and stored for later use.

Sometimes the amount of glucose circulating in your body surpasses what is needed for energy. When glucose becomes too concentrated in the blood, this is referred to as a glucose spike or a blood sugar spike. 

Some degree of rise in glucose is completely normal, but consistent spikes and the crashes that often follow can negatively impact your health and long-term well-being. Even if you don’t have diabetes or pre-diabetes, these constant ups and downs can take a toll, with research suggesting an increased risk for developing insulin resistance, type 2 diabetes, and cardiovascular issues (3,4).

Glucose spikes can also be caused by lifestyle factors such as stress or follow a poor night’s sleep. They can also occur during intense exercise, but in this case, a spike is a good thing.

You can take steps to limit or avoid glucose spikes and temper them once they start. Better glucose management can benefit your health in a number of ways, including how you feel, your energy levels, hunger and cravings, sleep, mental focus, and more. 

Here, we break down what a glucose spike is, what causes it, what they feel like, and how to avoid them in the future. Once you get a better understanding of how glucose works in your body, you can take steps to make healthier choices that will improve your well-being.  

What is a glucose spike?

A glucose spike, also known as a blood sugar spike, is a sharp, marked rise in the amount of glucose in your blood, typically followed by a comparable decline, also known as a crash. While it is normal for your glucose to rise and fall many times throughout the day, a true spike is different.  

Spikes occur for a myriad of reasons, most commonly after eating an influx of carbs and/or sugar (more on that later) but can also arise due to physiological and psychological stress, intense exercise, dehydration, caffeine intake, certain medications, and other factors.

When you have access to monitor your glucose levels with a continuous glucose monitor (CGM) like Lingo, you can see your glucose value throughout the day. Metabolically healthy individuals should strive to stay within 70-140mg/dL (3.9-7.8 mmol/L) and those with tighter glucose control will strive to stay within the range of 70-100mg/dL (3.9-5.6mmol/L).   

Most healthy individuals stay within the wider range most of the time. It’s typical to be out of the 70-140 mg/dl  (3.9-7.8mmol/L) range for just 30 minutes to 2 hours a day. (7) Sharp upticks above your average glucose value or above the recommended range are commonly defined as spikes. These excursions look like steep mountains on your Lingo glucose graph.

Your goal is to stay within the range of 70-140mg/dL (3.9-7.8mmol/L) most of the time and minimise the occurrence and severity of spikes. With Lingo, coaching prompts, your Lingo Count, and Lingo glucose graph can help you understand when you’re spiking so you can begin to discover the why behind your spikes and make changes to stay steady.  

What causes a glucose spike?

A glucose spike typically happens after eating something particularly carb-heavy, especially if the carbohydrates are mostly simple carbs (e.g. white bread, pasta, bagel) and sugar. A glucose spike can also occur if you eat carbohydrates by themselves; pairing a carb with a source of protein or fat can help limit the glucose impact and reduce the risk of a spike. 

High-intensity exercise can also cause a glucose spike because it increases adrenaline (the fight-or-flight hormone), which signals to your body that it’s time to break down liver glycogen to glucose. This quick influx of fuel can spike your glucose, but as mentioned, a spike is a good thing in this instance. In the same way that exercise spikes your heart rate temporarily but provides benefit in the long run, a temporary blood glucose rise with exercise is an example of hormesis, which is a short-term stress that enables long-term adaptation.

Other lifestyle factors may influence glucose, such as stress and poor sleep. Like with intense exercise, an increase in stress triggers the stress hormones cortisol and adrenaline, which can raise your glucose as your body needs quick energy to enter into fight-or-flight mode. Not getting enough sleep can disrupt your body’s ability to use glucose, causing future health concerns. (5)

Over time this may lead to metabolic issues like prediabetes or type 2 diabetes, a disorder in which your body becomes resistant to insulin and loses its ability to properly remove glucose from the blood into your cells to use for energy. 

What does a glucose spike feel like?

While a glucose spike may feel differently for each person, some common symptoms include tiredness, thirst, and hunger. Alternatively, some people may be asymptomatic and not notice when they are spiking.

As your glucose rises, your body releases insulin to manage the extra glucose. As insulin circulates, your glucose rapidly lowers, often leading to a sharp crash. When this happens, your body typically craves more simple carbohydrates and sugar for a quick energy boost, and if you answer the craving, the spike-crash cycle continues. (6)

Another major sign of a glucose spike followed by a crash is the feeling of being “hangry” (hungry + angry) in which you may feel irritable while also feeling hungry. This feeling often stems from a drop in glucose that signals an increase in ghrelin, known as the hunger hormone. This triggers a cascade of other hormones including the stress hormone cortisol, which explains why you feel irritable or impulsive in addition to physical hunger pangs.  

While hanger caused by low glucose can happen when you undereat or go too long in between meals, it can also happen in high glycaemic diets in which your glucose levels are constantly spiking and crashing. 

After you eat something with a lot of carbs and notice symptoms of a spike, incorporating movement may help temper the spike. A brisk 10-minute walk after eating may be all you need to prevent or lessen a glucose spike. Other quick bursts of exercise can also help, such as 10 minutes of bodyweight squats, jumping jacks, lunges, and calf raises. It’s a good idea to drink plenty of water and opt for something with more protein at your next meal.

What is the impact of glucose spikes?

In the short term, glucose spikes can cause hunger, cravings, feelings of fatigue, impact mood, and interfere with your sleep. While you’re likely to notice these effects as they're happening, there is impact behind the scenes, too. Glucose spikes can significantly impact the health of blood vessels and cells, with chronic spikes setting the stage for metabolic dysfunction.  

Elevated glucose increases your risk for developing insulin resistance and type 2 diabetes, causes inflammation, and impacts your blood vessels, which can lead to cardiovascular issues like heart disease. (3,4)

This is why it’s important to limit the number and size of glucose spikes that occur. Wearing a continuous glucose monitor like Lingo can help you learn about your glucose and track your spikes. Lingo provides real time data and coaching to help you understand how your habits impact your glucose and metabolic health.

With Lingo, you’ll learn to limit the size and frequency spikes and make changes to improve your overall metabolic well-being, which can lead to more energy, better sleep, less hunger and cravings, and increased focus.

How to avoid a glucose spike

There are many ways to avoid a glucose spike naturally, and the best method is to be thoughtful with your food choices. Limit foods that are common sources of spikes such as refined carbohydrates, sugars, and sugary beverages, and instead opt for more complex carbohydrates that have fibre such as vegetables, fresh fruit, brown rice, quinoa, and whole grain bread. Even better, pair your carbohydrates with a source of protein and/or fat for a macronutrient-balanced option. 

Other lifestyle habits that can help keep your glucose steady include getting quality sleep, staying physically active, drinking plenty of water, managing stress, and limiting alcohol. 

A final note from Lingo

While glucose spikes are normal and occur in healthy individuals, there are plenty of health benefits to managing your glucose and reducing the size and frequency of spikes. Maintaining steady glucose can help improve your metabolic health and give you more energy, better sleep, reduce hunger and cravings, and boost mental focus. 

Using a continuous glucose monitor like Lingo can help you understand your habits and patterns and work towards limiting glucose spikes.  

Lingo is not a medical device and not designed to treat or diagnose any disease or illness. If you have medical questions or concerns regarding your glucose, please contact your doctor.

Published: November 22, 2023. Last updated: February 29, 2024


  1. Patricia JJ, Dhamoon AS. Physiology, Digestion. [Updated 2022 Sep 12]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK544242/ 
  2. Goodman BE. Insights into digestion and absorption of major nutrients in humans. Adv Physiol Educ. 2010 Jun;34(2):44-53. https://pubmed.ncbi.nlm.nih.gov/20522896/  
  3. Jarvis PRE, Cardin JL, Nisevich-Bede PM, McCarter JP. Continuous glucose monitoring in a healthy population: understanding the post-prandial glycemic response in individuals without diabetes mellitus. Metabolism. 2023 Sep;146:155640.  https://pubmed.ncbi.nlm.nih.gov/37356796/ 
  4. O'Keefe JH, Gheewala NM, O'Keefe JO. Dietary strategies for improving post-prandial glucose, lipids, inflammation, and cardiovascular health. J Am Coll Cardiol. 2008 Jan 22;51(3):249-55.  https://pubmed.ncbi.nlm.nih.gov/18206731/  
  5. Yoshimura E, Hamada Y, Hatanaka M, Nanri H, Nakagata T, Matsumoto N, et al. Relationship between intra-individual variability in nutrition-related lifestyle behaviors and blood glucose outcomes under free-living conditions in adults without type 2 diabetes. Diabetes Res Clin Pract. 2023;196:110231. https://pubmed.ncbi.nlm.nih.gov/36565723/  
  6. Chandler-Laney PC, Morrison SA, Goree LL, Ellis AC, Casazza K, Desmond R, et al. Return of hunger following a relatively high carbohydrate breakfast is associated with earlier recorded glucose peak and nadir. Appetite. 2014;80:236-41. https://pubmed.ncbi.nlm.nih.gov/24819342/ 
  7. Shah VN, DuBose SN, Li Z, Beck RW, Peters AL, Weinstock RS, Kruger D, Tansey M, Sparling D, Woerner S, Vendrame F, Bergenstal R, Tamborlane WV, Watson SE, Sherr J. Continuous Glucose Monitoring Profiles in Healthy Nondiabetic Participants: A Multicenter Prospective Study. J Clin Endocrinol Metab. 2019 Oct 1;104(10):4356-4364. doi: 10.1210/jc.2018-02763. Erratum in: J Clin Endocrinol Metab. 2022 Mar 24;107(4):e1775-e1776. PMID: 31127824; PMCID: PMC7296129. https://pubmed.ncbi.nlm.nih.gov/31127824/  

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