Dizzy on Keto? It Could Be a Keto Diet Side Effect
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Dizzy on Keto? It Could Be a Keto Diet Side Effect

Dizzy on Keto? It Could Be a Keto Diet Side Effect
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Updated on July 31, 2025
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Low-carb diets like the keto diet are extremely popular, but some people complain they get dizzy, especially when they're first starting out.

One of the primary goals of the keto diet is to put your body in a state of nutritional ketosis. This is when your body burns fat for its primary fuel source instead of the glucose provided by carbs.

Nutritional ketosis is generally safe for most people, but it can come with some noticeable side effects, dizziness in particular.

Here's why the lack of carbs on a ketogenic diet may cause you to feel dizzy and what you can do about it.

Electrolyte and Fluid Imbalances

As you transition into ketosis, your body burns through your glycogen stores, the backup supply of carbs stored in your muscles and liver.

These carbs are stored with large amounts of water, which contain electrolytes, such as potassium and sodium, that help regulate your body's fluid balance.

As you burn through your glycogen stores, all of the water and electrolytes they contain are flushed out through your urine. This can cause dizziness if you're not drinking enough, not adding enough salt to your diet, or both, according to Jean LaMantia, RD, a registered dietitian in private practice in Toronto.

These fluid losses can easily lead to dehydration, which can cause extreme thirst, dry mouth, dry skin, fatigue, and dizziness.

Additionally, electrolyte losses may also cause dizziness because they can lower your blood pressure, says LaMantia. When there are huge shifts in electrolyte levels, such as those that occur when you first start keto, you're also likely to experience so-called “keto flu” symptoms. These might include headache, foggy brain, fatigue, nausea, and constipation, among others.

Low Blood Sugar Levels

Another reason low-carb diets may cause dizziness is because of changes in your blood sugar levels. "When you start on a low-carb diet, the level of sugar in your blood will reduce," says LaMantia. "It's possible your body could respond to this with low blood sugar."

Symptoms of low blood sugar levels include dizziness, shakiness, nervousness, sweating, confusion, increased heart rate, and hunger. Low blood sugar levels can be dangerous, especially in people with diabetes.

If you have type 1 or type 2 diabetes, speak to your doctor before starting a low-carb or keto diet, especially if you're taking any blood sugar-lowering medications, such as metformin or insulin.

Avoiding Keto Dizziness

One way to avoid or at least minimize dizziness on low-carb or keto diets is to stay adequately hydrated. Make an effort to drink water regularly and avoid beverages that tend to be dehydrating, such as those with caffeine, sugar, or alcohol. You should be drinking enough for your urine to be clear or pale yellow.

While the standard recommendation is to drink eight 8-ounce glasses of water per day, that number can vary depending on someone’s sex, activity level, and environment.

Additionally, according to LaMantia, if you tend to experience low blood sugar, proceed more cautiously with a low-carb diet. She suggests slowly easing into the diet rather than suddenly decreasing your carb intake.

The Takeaway

  • The keto diet severely restricts carbohydrate intake. This puts the body into a state of ketosis, which causes your body to burn fat instead of carbs.
  • It's not uncommon to experience dizziness among other symptoms early in the diet. This is sometimes known as the “keto flu.”
  • To avoid dizziness, it’s important to stay well hydrated and slowly ease into the diet. If you have diabetes, talk to your doctor before starting a keto diet.
EDITORIAL SOURCES
Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.
Resources
  1. Ketosis. Cleveland Clinic. August 15, 2022.
  2. Bostock ECS et al. Consumer Reports of "Keto Flu" Associated With the Ketogenic Diet. Frontiers in Nutrition. March 13, 2020.
  3. Low Blood Glucose (Hypoglycemia). American Diabetes Association.
  4. Deyhdration. Cleveland Clinic. June 5, 2023.
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Melissa Sleight, RDN

Medical Reviewer
Member of American College of Lifestyle Medicine
Melissa Sleight, RDN, is a board-certified lifestyle medicine dietitian with over 15 years of experience. She has a passion for educating her clients about improving their health through nutrition and lifestyle changes, and seeing them motivated to improve their health each day.

Sleight earned her bachelor's in nutrition and food science from Utah State University. She is a member of the American College of Lifestyle Medicine and the Sports, Cardiovascular, and Wellness Nutrition group for the Academy of Nutrition and Dietetics. She is involved at the local level as the president-elect of Magic Valley Dietitians and is a liaison for her community as a board member of the Idaho Academy of Nutrition and Dietetics.

She likes to cook and try new recipes, and loves water activities of all kinds — from paddleboards to hot tubs. She enjoys exploring the outdoors through hiking, on all-terrain vehicles, and camping.
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SaVanna Shoemaker, MS, RDN, LD

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SaVanna is a registered dietitian and health writer.

As a registered dietitan, SaVanna has worked with pregnant and postpartum women, infants and children, people with chronic kidney disease, and people who are critically ill. She is particularly interested in culinary and functional nutrition for weight loss and female hormone health.

She's currently a contributor for Forbes Vetted, Sports Illustrated Showcase, Mashable, and Carb Manager, and her work has also appeared in Greatist, mindbodygreen, and Bicycling Magazine, among other outlets.

SaVanna lives with her husband and three kids in Little Rock, Arkansas. She enjoys cooking, baking, gardening, and weightlifting.

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