The fastest way to get rid of ketones in urine is to drink water and, if you have diabetes, take insulin as directed. Ketones appear in urine when your body burns fat instead of glucose for energy, and the fix depends entirely on why that’s happening. For people with diabetes, elevated ketones can signal a dangerous shift toward ketoacidosis. For others, ketones may simply reflect fasting, a low-carb diet, or intense exercise.
Why Ketones Show Up in Urine
Your body’s preferred fuel is glucose. When glucose isn’t available or your cells can’t use it properly, your liver breaks down fat and produces ketones as an alternative energy source. Those ketones circulate in your blood, and once levels rise high enough, your kidneys start filtering them into your urine.
Common triggers include skipping meals, following a very low-carb or ketogenic diet, prolonged exercise, illness, dehydration, and insufficient insulin in people with diabetes. In most healthy people, ketone production stays within a safe range. Blood ketone levels normally fluctuate between roughly 100 and 250 micromoles per liter throughout the day and can rise to around 1 millimole per liter after extended exercise or a full day of fasting. That level is manageable. The concern starts when ketones climb higher, especially in someone with diabetes.
Hydration Is the First Step
Water helps your kidneys flush ketones out of your bloodstream and into your urine more efficiently. When you’re dehydrated, ketones concentrate in your blood and urine because there’s less fluid to dilute and carry them away. Drinking water won’t stop your body from producing ketones, but it accelerates their removal and helps prevent the acid buildup that makes high ketones dangerous.
Aim for steady intake rather than gulping large amounts at once. Sipping water consistently over several hours gives your kidneys time to process the fluid. If you’ve been vomiting or unable to keep fluids down (common during illness), that’s a reason to seek medical help, because dehydration and rising ketones can spiral quickly.
Eat Enough Carbohydrates
If ketones are showing up because you’ve been fasting or eating very few carbs, reintroducing carbohydrates is the most direct solution. When your body has glucose available again, it shifts back to burning glucose and slows ketone production. A meal or snack with 15 to 30 grams of carbohydrates, like a piece of fruit, crackers, or juice, can start that shift within a couple of hours.
People following a ketogenic diet will naturally have some level of ketones in their urine. That’s the intended effect of the diet. If you’re otherwise healthy and intentionally in ketosis, trace or small amounts of urinary ketones aren’t a medical problem. But if you’re concerned about persistent high readings, increasing your carb intake even modestly will bring levels down.
Insulin and Diabetes Management
For people with type 1 diabetes, and sometimes type 2, ketones in urine often mean insulin levels are too low. Without enough insulin, your cells can’t absorb glucose from the blood, so your body turns to fat for fuel and produces ketones. The fix is correcting your insulin. If you use an insulin pump, check for kinks, air bubbles, or a dislodged infusion site. If you inject insulin, make sure you haven’t missed a dose or that your insulin hasn’t expired or been exposed to heat.
Illness is a major trigger for rising ketones in diabetes because stress hormones make your body more resistant to insulin. During sick days, your insulin needs may actually increase even if you’re eating less. Testing your ketones every two to four hours during illness helps you catch a dangerous rise early. Most diabetes care teams provide a “sick day plan” with adjusted insulin guidance for exactly this situation.
Know When Ketones Are Dangerous
Diabetic ketoacidosis (DKA) is a medical emergency that happens when ketones build up to the point where they make your blood dangerously acidic. It develops most often in type 1 diabetes but can occur in type 2 as well, particularly during severe illness or infection.
If you’re testing blood ketones with a meter, the NHS provides a clear scale: readings under 0.6 mmol/L are normal, 0.6 to 1.5 mmol/L is slightly high and worth rechecking in two hours, 1.6 to 3.0 mmol/L puts you at risk for DKA and warrants a call to your diabetes care team, and anything over 3.0 mmol/L means DKA may already be developing and you need emergency care. If you’re using urine test strips, a reading of 2+ or higher suggests possible DKA.
Symptoms of DKA include nausea, vomiting, abdominal pain, rapid breathing, fruity-smelling breath, and confusion. These can develop over just a few hours. DKA requires IV fluids and insulin in a hospital setting, along with careful monitoring of electrolytes. Potassium levels in particular can swing dangerously during treatment, which is one reason DKA isn’t something to manage at home once it’s underway.
Exercise: Helpful Sometimes, Harmful Other Times
Physical activity has a complicated relationship with ketones. During exercise, your muscles actually burn ketones as fuel, which can keep levels from spiking. But after you stop exercising, your body continues breaking down fat at an elevated rate, producing more ketones than your muscles are now using. This post-exercise ketosis is temporary in healthy people and resolves on its own.
The important exception is for people with diabetes whose blood sugar is already high (typically above 250 mg/dL) and who have ketones present. Exercising in that state can worsen ketone production because your body is already short on usable insulin. In that scenario, exercise makes the problem worse, not better. Correct the insulin deficit and bring blood sugar down first, then resume activity once ketones have cleared.
Electrolytes Matter When Flushing Ketones
Drinking extra water to clear ketones also flushes out electrolytes, particularly sodium, potassium, and magnesium. If you’re aggressively hydrating over several hours or days, replacing those minerals prevents muscle cramps, fatigue, heart palpitations, and lightheadedness. Broth, electrolyte drinks, or foods rich in potassium (bananas, avocados, spinach) help maintain balance.
This is especially relevant for people on ketogenic diets, who tend to run low on electrolytes already because low insulin levels cause the kidneys to excrete more sodium. Adding salt to food and supplementing with magnesium can reduce the headaches and fatigue sometimes blamed on ketosis itself but actually caused by mineral depletion.
How Long It Takes for Ketones to Clear
With adequate hydration and, if applicable, proper insulin dosing, mild to moderate ketones typically clear from urine within 12 to 24 hours. Keep in mind that urine test strips reflect what was happening in your blood hours earlier, so they lag behind real-time changes. Blood ketone meters give a more current reading. If you’re tracking your progress, blood testing tells you sooner that levels are dropping, while urine strips may still read positive even after your blood levels have normalized.
If ketones haven’t improved after several hours of hydration and carbohydrate intake, or if they’re climbing despite your efforts, that pattern points to an underlying issue that needs professional evaluation, particularly inadequate insulin or an undiagnosed condition affecting glucose metabolism.