Ketonuria Pathophysiology: Causes, Symptoms & Diagnosis

Ketonuria is a medical condition in which abnormally large amounts of ketones in urine excrete out from your body. This is also known as ketoaciduria and acetonuria. It can be an indication of diabetes ketoacidosis, starvation, or other medical condition. Ketones are normally produced in our bodies when fatty acids or proteins burnt out. It is a normal procedure that occurs in all humans, but if it’s overdrive, it can cause Ketonuria.

This ketoaciduria is common in diabetes mellitus especially type 1 diabetes mellitus and in those women who are pregnant and breastfeeding. During starvation, when your body cells don’t get enough glucose, your extra body fat catabolizes to provide glucose molecules. During this catabolism ketones are produced as a byproduct, therefore, starvation can also be a cause of Ketonuria.

What Are The Causes Of Ketonuria Or Ketoaciduria?

Many medical conditions can cause acetonuria, but the most common causes are the following, which are mostly seen in such patients.

1- Diabetes Mellitus/ Low Insulin Level

Most of your body energy comes from stored glucose or proteins. This glucose comes from the carbohydrates which you eat in our meal. When you take a meal, the amount of glucose raised in your blood as carbohydrates ultimately convert into glucose or sugar. Therefore, to lower this sugar after a meal, a natural hormone is produced in our body i.e INSULIN.

Insulin hormone produced from the beta cells of the pancreas in the response to raised blood glucose. This insulin attached to the glucose molecule and get entry into the body tissues and let them stored. These body tissues may be adipose tissue of your abdomen, muscles, heart, or liver.

Such humans which have a low level of insulin, their body is unable to store the glucose and can’t use it as a fuel. During this body starvation, despite high blood glucose, the body uses other sources to get energy such as fatty acids. Body fats and proteins are broken down into fatty acids for energy, producing ketones as a byproduct.

If insulin deficiency persists for a prolonged time, these ketones keep on producing as a waste product and when ketones are accumulated in your bloodstream, a condition called ketoacidosis or diabetic ketoacidosis can occur. This is a medical emergency when your blood is acidic and can harm your body organs.

Ketonuria usually happens after ketoacidosis. As ketones accumulated in your blood, your kidneys try to remove these extra ketones through the urine. This is the actual cause of Ketonuria in diabetic patients who have a low level of insulin because, without sufficient insulin, your body can’t properly absorb sugar from the digested food.


There are some conditions in which ketones level may raise in blood. These are

  • Pregnancy
  • Starvation
  • Drinking excess alcohol
  • Anxiety, emotional stress
  • Excess vomiting
  • Infection
  • Heart attack

Signs & Symptoms Associated With the Ketonuria

Ketonuria or ketoaciduria is itself a sign of insulin deficiency, but it may cause further body changes. The more the ketones are in the blood, severe the symptoms are and difficult to treat them. Depending on the level of ketones in blood and urine, signs and symptoms vary from patient to patient. The patient may present with the

  • fruity-smelling breath (Acidotic breathing, the most characteristic finding of ketoacidosis)
  • Thirst
  • dry mouth
  • Dehydration
  • nausea or vomiting
  • Abdominal pain
  • frequent urination
  • Fatigue
  • confusion
  • After having the labs, your doctor finds some signs
  • High ketones level in urine
  • High proteins level in urine
  • High blood sugar level
  • Electrolytes imbalance

How Ketonuria Can Be Diagnosed?

It is diagnosed clinically.

  • Proper medical history
  • Physical examination of signs & symptoms
  • Urine test

Ketonuria is diagnosed through a urine test by taking a sample of urine.

  • Finger-stick ketone blood test
  • Acetone Breath test
  • Complete blood count
  • Blood electrolytes
  • Blood glucose test ( after every 30 minutes)
  • Blood culture for infections
  • Chest x-ray
  • CT-scan

Complete Management of Ketonuria

Treatment of Ketonuria depends on the cause of this ketoaciduria.

1. Ketonuria Due to starvation

If these changes in ketones are due to starvation, then it resolves on its own. There is no need for any particular treatment.

2. Ketonuria Due to Diabetes

If the patient has a past medical history of diabetes mellitus, then your doctor starts treatment in a sequence. Your doctor start lifesaving treatment with

  • Fast-acting insulin, according to your blood glucose level
  • Plenty of I/V fluids i.e Normal Saline or 5% dextrose
  • Electrolytes such as sodium, chloride, and potassium

3. Ketonuria Due to Illness

If accumulated ketones are due to Illness, then your doctor provides you some extra treatment along with the above treatment.

  • Antibiotics
  • Antivirals

During this treatment, your physician keeps on checking your blood glucose level after every 30 minutes to monitor the compliance of the patient. Also, keep on monitoring the urine output of such patients. These patients are critical at this stage because their electrolytes imbalance can harm the body. Therefore, fluid and electrolytes should also be maintained along with blood glucose.


If this Ketonuria is left untreated, undiagnosed or unchecked, it may cause serious life-threatening complications such as

  • Coma
  • Seizures
  • Cardiac Arrhythmias
  • Severe Dehydration
  • Respiratory distress
  • Myocardial infarction
  • DVT
  • CVT

An altered state of consciousness

Therefore, diabetic patients must have an awareness of this condition before. If you experience a fruity breathing smell or such symptoms, immediately consult your healthcare provider to control it.

HP Thoughts: Kidneys play an important function in your body since this body part manages the proper filtration of waste materials. Once its role fails, then the entire body suffers considerably. One of the worst-case scenarios would be this — Acute Renal Failure.

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