What to do if ketosis is too high? A guide to managing ketone levels

October 28, 2025 •

4 min read

For people with diabetes, high ketones are a critical warning sign that can precede a life-threatening condition called diabetic ketoacidosis (DKA). Knowing what to do if ketosis is too high is vital for preventing serious health complications, whether on a ketogenic diet or managing diabetes.

Quick Summary

This guide outlines the critical differences between healthy nutritional ketosis and the dangerous state of ketoacidosis (DKA), including symptoms, testing protocols, and safe management strategies. Proper hydration, carbohydrate adjustment, and recognizing medical emergency signs are emphasized.

Key Points

Understand Your Level: Use a blood ketone meter to accurately measure your ketone levels, distinguishing between normal nutritional ketosis (0.5-3.0 mmol/L) and dangerous levels (>3.0 mmol/L).
Monitor Symptoms: Be vigilant for signs of ketoacidosis (DKA) such as extreme thirst, frequent urination, nausea, vomiting, or fruity-smelling breath, especially if you have diabetes.
Stay Hydrated: Drinking plenty of water is essential for flushing out excess ketones, particularly with sugar-free fluids if blood sugar is high.
Adjust Carbohydrates: If levels are too high for nutritional ketosis, reintroduce small amounts of healthy carbohydrates gradually to help reduce ketone production.
Seek Medical Help: If you are experiencing DKA symptoms or your blood ketones exceed 3.0 mmol/L, seek immediate medical attention.

Understanding Your Ketone Levels

Ketosis is a metabolic state where the body burns fat for energy instead of glucose. For many following a ketogenic diet, achieving and maintaining a state of nutritional ketosis is the goal, typically measured by blood ketone levels between 0.5 and 3.0 mmol/L. However, ketone levels can rise higher, and when combined with other factors, can become dangerous. It is crucial to distinguish between healthy ketosis and a medical emergency called diabetic ketoacidosis (DKA).

The Critical Difference: Ketosis vs. Ketoacidosis

Ketosis and ketoacidosis sound similar but are two very different conditions. In nutritional ketosis, your body is producing ketones from fat to use as fuel because of carbohydrate restriction, but your blood chemistry remains balanced. With ketoacidosis, often a complication of diabetes, ketones build up to toxic levels because of a severe lack of insulin, making the blood dangerously acidic.

Nutritional Ketosis: A controlled metabolic state induced by a low-carb diet. Typically monitored and managed without medical intervention for non-diabetics.
Diabetic Ketoacidosis (DKA): A life-threatening medical emergency. High ketone levels and high blood sugar occur due to insufficient insulin, causing the blood to become acidic.

Recognizing Signs of Dangerously High Ketones

Symptoms of DKA can come on quickly, sometimes within 24 hours. If you are experiencing any of the following, you should seek immediate medical attention, especially if you have diabetes or are feeling unwell:

Frequent urination and extreme thirst
Nausea, vomiting, or abdominal pain
Shortness of breath or rapid, shallow breathing
Fruity-smelling breath
Fatigue, confusion, or weakness

Immediate Actions for High Ketones

If you test your ketones and find they are elevated, or if you experience any concerning symptoms, taking immediate action is essential. Do not ignore your results, especially if you have diabetes.

Test your levels: Use a blood ketone meter to get an accurate reading. Levels above 3.0 mmol/L should be treated as a medical emergency.
Hydrate Immediately: Drink plenty of fluids. If your blood sugar is high, choose sugar-free beverages like water. If blood sugar is low, opt for liquids with sugar like juice. Staying hydrated helps flush excess ketones from your system.
Do not Exercise: If your blood sugar is high and ketones are present, avoid exercise. Physical activity can increase ketone levels further.
Contact your doctor: If blood ketones are between 1.6 and 3.0 mmol/L, call your doctor or diabetes team for advice. They may instruct you on how to adjust your medication or insulin.
Emergency Services: If your blood ketones are over 3.0 mmol/L, or you are experiencing severe symptoms like persistent vomiting or confusion, go to the emergency room or call emergency services immediately.

Safely Lowering Ketones After a Keto Diet

For those who are not diabetic and find their ketone levels consistently too high for comfort or for athletes looking to strategically increase carb intake, reintroducing carbohydrates safely is the best approach.

Reintroduce Carbs Gradually: Begin by adding 10 grams of carbs per day and slowly increase from there. Rushing to add a lot of carbohydrates can cause stomach upset and bloating.
Choose Healthy Carbohydrates First: Prioritize unprocessed, high-fiber carbs like fruits and vegetables. Good examples include berries, carrots, and squash. Avoid sugary and processed carbs, which can cause blood sugar spikes and cravings.
Include Lean Protein: As you decrease fat intake, increase your lean protein to help with satiety and energy. This helps prevent overeating and unnecessary weight gain.
Listen to Your Body: Pay attention to how you feel. It can take up to two weeks for your body to fully adjust to the shift in energy sources. Monitor your energy, digestion, and any bloating.

Comparison Table: Ketone Levels and Actions


Blood Ketone Level (mmol/L)	Interpretation	Recommended Action
Below 0.5	Not in ketosis.	Follow dietary plan to enter ketosis.
0.5 – 1.5	Mild Nutritional Ketosis.	Generally safe; continue monitoring.
1.6 – 3.0	Optimal/High Nutritional Ketosis.	Monitor symptoms and contact your doctor if you have diabetes or feel unwell.
Above 3.0	Ketoacidosis Risk (Medical Emergency).	Seek immediate medical attention (ER) or call emergency services.

Conclusion

Understanding what to do if ketosis is too high is primarily about differentiating between a controlled metabolic state and a dangerous medical condition. While non-diabetics on a ketogenic diet can typically manage higher ketone levels by adjusting their carbohydrate intake and staying hydrated, individuals with diabetes must be vigilant for signs of DKA. In any case of moderate to high ketones, especially with accompanying symptoms like persistent vomiting or confusion, prompt medical consultation is non-negotiable. Always listen to your body and work with a healthcare provider, especially when making significant dietary changes like transitioning off keto.

For more information on preventing and managing DKA, you can visit the CDC's website on Diabetic Ketoacidosis.

Frequently Asked Questions

A safe and optimal range for nutritional ketosis is typically between 0.5 and 3.0 mmol/L in the blood.

Symptoms of dangerously high ketones, which indicate ketoacidosis (DKA), include extreme thirst, frequent urination, nausea, vomiting, abdominal pain, confusion, and fruity-smelling breath.

You should go to the hospital or call emergency services immediately if your blood ketone levels are over 3.0 mmol/L, you are vomiting repeatedly, or you are experiencing severe symptoms of DKA.

Ways to lower ketones include increasing fluid intake, cautiously reintroducing carbohydrates, and, for diabetics, taking insulin as prescribed by a doctor.

No, you should not exercise if your blood sugar is high and ketones are present. Physical activity can cause ketones to rise further in this state.

Nutritional ketosis is a mild metabolic state where the body uses fat for fuel, while ketoacidosis is a dangerous, life-threatening condition where high ketone levels make the blood too acidic.

Reintroduce carbohydrates slowly, starting with nutrient-dense options like fruits and vegetables. Avoid processed sugars and listen to your body's response.