Table of ContentsView AllTable of ContentsThe Dangers of KetosisWhat Causes Ketosis?Ketosis vs. KetoacidosisKetogenic Diet vs. Low CarbHow to Reach Ketosis Safely
Table of ContentsView All
View All
Table of Contents
The Dangers of Ketosis
What Causes Ketosis?
Ketosis vs. Ketoacidosis
Ketogenic Diet vs. Low Carb
How to Reach Ketosis Safely
Ketosisis an alternative form of metabolism where your body uses ketone bodies as its primary energy source instead of glucose (sugar). Typically, ketosis kicks in when glucose is in short supply, such as during fasting, strenuous exercise, or a very low-carbohydrate diet.
Ketosisis a normal metabolic process but can be dangerous under certain conditions. It typically occurs when your body doesn’t have enough glucose (sugar) due to starvation or intense exercise. Your body then starts using ketone bodies made from stored fat.
Though ketosis offers benefits like weight loss and improved insulin sensitivity, it’s essential to consider its potential risks.For example, it can be risky for those with specific health conditions such as the following:
Exercise additional caution if you have type 1 diabetes or are on blood sugar-lowering medications.You may need to change your medication regimen or make dietary changes to avoid hypoglycemia.
Consult with your healthcare provider before starting a keto diet, especially for people with diabetes or pregnant or breastfeeding women.
Additionally, ketosis might lead to kidney stones, mainly if protein intake is excessive.Careful management of the fat-to-protein ratio is recommended to avoid such issues.
1. It May Cause Dehydration
Dehydration is a common early side effect of ketosis. Fortunately, it’s usually short-lived and treatable. You may experience dehydration early on while in ketosis because of changes inelectrolytesthat influence hydration. Research shows that the kidneys may excrete more sodium than usual from days two through six of ketosis.
To treat or prevent dehydration symptoms, drink plenty of water and other hydrating beverages while in ketosis.
Over-the-counter pain medications can also treat aheadachewhen necessary.
2. It Can Cause Constipation
Some people experienceconstipationwhile in ketosis or following the keto diet. Ketosis may cause constipation and other digestive issues to arise due to the extreme nature of the diet changes.
Common symptoms of constipation include:
To combat constipation while in ketosis, drink plenty of fluids and try to include fiber where possible. Afiber supplementmay be helpful for some people, while others may need to use alaxativeorenemato find relief.
Talk with your healthcare provider about how to safely use laxatives and enemas.
Is Almond Flour Keto-Approved?
3. It Can Cause Electrolyte Imbalances
Extreme diet changes, such as those required on the keto diet, may causeelectrolyte imbalances. They are typically seen early in ketosis (the first several days). An electrolyte imbalance may occur when the levels of one or more electrolytes are too low or too high.
Hyponatremia (low sodium) and hypomagnesemia (low magnesium) are common electrolyte imbalances in ketosis. Electrolyte imbalances may be due to dehydration, excretion of ketone bodies and electrolytes, and lowmicronutrientintake.
Electrolyte imbalance symptoms may include:
Electrolyte replacement beverages and supplements are typically consumed to treat low electrolyte levels. In the case of high electrolyte levels, certain medications or extra fluids may help.
Not everyone in ketosis will experience symptoms of an electrolyte imbalance. Your healthcare provider can provide further guidance.
4. It May Cause Keto Flu
Since becoming popular, the keto diet has been associated with something called theketo flu. It may occur in the first few weeks of starting the keto diet and reaching ketosis.
It’s often confused with other illnesses and may cause some people to stop the keto diet early on.Symptoms of the keto flu tend to vary but may mimic those of the flu.
According to one study, people who have experienced the keto flu reported:
These and other keto flu symptoms should go away within four weeks as your body adjusts to ketosis.
Increasing your intake of water and electrolytes may help treat the keto flu.
If you get the keto flu, talking with a healthcare provider about ways to feel better is best.
5. It May Lower Your Blood Sugar Too Much
Some researchers believe the keto diet can help lower blood sugar levels, but it can also cause blood sugar to drop too low for some individuals.
Carbohydrates have the most direct effect on blood sugar levels. So, the very low carb intake during ketosis may lead tohypoglycemia(low blood sugar).Drops in blood sugar are of particular concern for people with diabetes.
In a small study, people with type 1 diabetes on the keto diet had an average of 6.3 episodes of low blood sugar per week, compared to one to two episodes per week on a less restrictive diet.
Symptoms of low blood sugar include the following:
Hypoglycemia may also be more likely in people who take blood sugar-lowering medications.
If you take such medications, talk with your healthcare provider about tapering diabetes medications to prevent low blood sugar before starting the keto diet.
6. It Can Cause Nutrient Deficiencies
These deficiencies may lead to decreased cognitive function, respiratory infections, vision loss, bone loss, gastrointestinal problems, fatigue, and more.You may need to take a multivitamin or other supplements to avoid nutrient deficiencies in ketosis.
Talk with your healthcare provider for individualized guidance.
7. It May Cause Cardiovascular Risks
Research suggests that the keto diet may increase the risk of specific cardiovascular issues.
Though it can quickly lower triglycerides, blood pressure, and body weight, its long-term benefits for heart health remain unclear.
A review found that the keto diet correlated with higher total and low-density lipoprotein (LDL) cholesterol levels than diets with 45% to 65% carbohydrates.However, other studies in the review showed no significant differences in lipid profiles after three, six, or 12 months on the keto diet.
The potential risks are thought to be related to the high intake of animal-based products and saturated fats, which are linked to atherosclerosis and cardiovascular diseases.
To assess your cardiovascular risk, consider having a healthcare provider perform a lipid panel. Your risks may decrease after stopping the keto diet.
8. It May Cause Kidney Issues
Ketosis can negatively impact your kidneys, potentially leading to acute or chronic issues.
The keto diet has been associated with a higher risk of kidney stones, in part due to ketones making urine more acidic. Increased kidney stones may also result from people unintentionally eating more animal-based foods and protein than is recommended for this diet.
Signs of kidney stones include the following:
For people with chronic kidney disease (CKD), ketosis may worsen conditions and increase the risk of complications like metabolic acidosis. If left untreated, metabolic acidosis may cause:
Consult a healthcare provider before starting a keto diet if you have CKD or other kidney problems to see if it’s safe for you.
Ketosis occurs when your body usesketone bodiesfor energy instead of carbohydrates. This can happen for several reasons:
Signs of ketosis include dehydration, constipation, and “keto flu.” Testing your blood or urine for ketones can usually confirm ketosis.
Ketosisis a metabolic state in which the body uses ketone bodies for energy instead of carbohydrates.
Ketoacidosisis a severe condition in which ketone levels become dangerously high, making blood and urine too acidic.Ketoacidosis typically does not occur with ketosis. It typically occurs in diabetes, known as diabetic ketoacidosis (DKA). DKA is due to very low insulin levels and high blood sugar levels caused when glucose cannot enter cells.
Both ketosis and ketoacidosis involve high levels of ketones. However, ketoacidosis is life-threatening. Signs of ketoacidosis include the following:
Seek immediate medical attention if you have signs of ketoacidosis. Delaying treatment may be dangerous.
Ketogenic diets and low-carbohydrate diets (LCD) differ primarily in their carbohydrate and protein limits. The keto diet tends to have a higher percentage of fat, lower protein, and half the carbohydrates of the LCD. Carbohydrate sources tend to be from non-starchy vegetables and small amounts of berries.
The following outlines the typical percentage and amount of carbohydrates, protein, and fat per day needed for a 2,000-calorie diet for each diet.
Keto diet (very low-carbohydrate):
Low carbohydrate diet:
Ketosis is generally safe, but more research is necessary to understand its long-term effects and optimal methods for achieving it.To reach ketosis safely, it’s important to:
This cautious approach may help ensure you safely reach and maintain ketosis.
Summary
Ketosis is when your body turns fat into ketone bodies to use as fuel. It does this when carbohydrates are too low to be used for energy efficiently.
Research regarding the safety of ketosis is ongoing. The ketogenic diet has made ketosis highly popular over recent years. However, there are many possible short- and long-term side effects of ketosis and the ketogenic diet.
28 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Dilliraj LN, Schiuma G, Lara D, et al.The evolution of ketosis: potential impact on clinical conditions.Nutrients. 2022;14(17):3613. doi:10.3390/nu14173613
McGaugh E, Barthel B.A review of ketogenic diet and lifestyle.Mo Med. 2022;119(1):84-88.
Batch JT, Lamsal SP, Adkins M, et al.Advantages and disadvantages of the ketogenic diet: a review article.Cureus. 2020;12(8):e9639. doi:10.7759/cureus.9639
Sussman D, van Eede M, Wong MD, et al.Effects of a ketogenic diet during pregnancy on embryonic growth in the mouse.BMC Pregnancy Childbirth. 2013;13:109. doi:10.1186/1471-2393-13-109
Muscogiuri G, Barrea L, Laudisio D, et al.The management of very low-calorie ketogenic diet in obesity outpatient clinic: a practical guide.J Transl Med. 2019;17(1):356. doi:10.1186/s12967-019-2104-z
Rollet M, Bohn T, Vahid F, et al.Association between dietary factors and constipation in adults living in Luxembourg and taking part in the ORISCAV-LUX 2 survey.Nutrients. 2021;14(1):122. doi:10.3390/nu14010122
National Institute of Diabetes and Digestive and Kidney Diseases.Symptoms & causes of constipation.
MedlinePlus.Fluid and electrolyte balance.
Balcı AK, Koksal O, Kose A, et al.General characteristics of patients with electrolyte imbalance admitted to emergency department.World J Emerg Med. 2013;4(2):113-116. doi:10.5847/wjem.j.issn.1920-8642.2013.02.005
Alarim RA, Alasmre FA, Alotaibi HA, et al.Effects of the ketogenic diet on glycemic control in diabetic patients: meta-analysis of clinical trials.Cureus. 2020;12(10):e10796. doi:10.7759/cureus.10796
National Institute of Diabetes and Digestive and Kidney Diseases.Low blood glucose (hypoglycemia).
Kiani AK, Dhuli K, Donato K, et al.Main nutritional deficiencies.J Prev Med Hyg. 2022;63(2 Suppl 3):E93-E101. doi:10.15167/2421-4248/jpmh2022.63.2S3.2752
Popiolek-Kalisz J.Ketogenic diet and cardiovascular risk - state of the art review.Curr Probl Cardiol. 2024;49(3):102402. doi:10.1016/j.cpcardiol.2024.102402
Maki KC, Dicklin MR, Kirkpatrick CF.Saturated fats and cardiovascular health: current evidence and controversies.J Clin Lipidol. 2021;15(6):765-772. doi:10.1016/j.jacl.2021.09.049
Joshi S, Shi R, Patel J.Risks of the ketogenic diet in CKD – the con part.Clin Kidney J. 2023;17(1):sfad274. Published 2023 Nov 7. doi:10.1093/ckj/sfad274
National Institute of Diabetes and Digestive and Kidney Diseases.Symptoms & causes of kidney stones.
MedlinePlus.Ketones in blood.
MedlinePlus.Diabetic ketoacidosis.
Harvard T. H. Chan School of Public Health.Diet review: ketogenic diet for weight loss.
Barber TM, Hanson P, Kabisch S, et al.The low-carbohydrate diet: short-term metabolic efficacy versus longer-term limitations.Nutrients. 2021;13(4):1187. Published 2021 Apr 3. doi:10.3390/nu13041187
FoodData Central.Nuts, almonds.
FoodData Central.Avocados, raw, all commercial varieties.
FoodData Central.Fish, salmon, Atlantic, wild, cooked, dry heat.
FoodData Central.Beverages, protein powder whey based.
FoodData Central.Blueberries, raw.
Meet Our Medical Expert Board
Share Feedback
Was this page helpful?Thanks for your feedback!What is your feedback?OtherHelpfulReport an ErrorSubmit
Was this page helpful?
Thanks for your feedback!
What is your feedback?OtherHelpfulReport an ErrorSubmit
What is your feedback?
By clicking “Accept All Cookies”, you agree to the storing of cookies on your device to enhance site navigation, analyze site usage, and assist in our marketing efforts.Cookies SettingsAccept All Cookies
By clicking “Accept All Cookies”, you agree to the storing of cookies on your device to enhance site navigation, analyze site usage, and assist in our marketing efforts.
Cookies SettingsAccept All Cookies
