What Causes Sweet-Smelling Urine?

Sweet-smelling urine isn't normal, especially when the scent comes on suddenly. In some cases, it's caused by a serious condition that requires immediate treatment.

For instance, sweet-smelling urine is one of the possible symptoms of uncontrolled diabetes. It's also a classic symptom of a potentially life-threatening complication of diabetes known as diabetic ketoacidosis (DKA).

Outside of diabetes, there are other reasons why your urine (pee) may smell sweet, including bacterial urinary tract infections (UTIs), liver disease, and a rare genetic disorder called maple syrup urine disease.

This article goes into detail about the possible causes of sweet-smelling urine, including how the conditions are diagnosed and treated. It also explains when sweet-smelling urine may be a sign of a medical emergency in people with uncontrolled diabetes.

Reasons Why Your Urine Smells Sweet

Changes in the odor, color, and appearance of urine can happen for many reasons, and that's not necessarily a sign of a problem. However, sweet-smelling urine is almost always a sign of a medical condition.

Some of these conditions will get better with treatment, but others can be fatal. If you notice your pee smells sweet, tell your healthcare provider.

Hyperglycemia and Diabetes

Fruity-smelling urine is sometimes the first sign of diabetes. High blood sugar (hyperglycemia) is common in people with undiagnosed diabetes or poorly controlled diabetes.

High levels of sugar (glucose) in the urine can make it smell sweet or like fruity cereal. There are also other signs of high blood sugar, including:

• Excessive thirst
• Increased need to drink water
• Frequent urination

Diabetic Ketoacidosis (DKA)

Diabetic ketoacidosis (DKA) is a very serious, even life-threatening, condition where chemicals called ketones to build up in the blood. Too many ketones make the blood too acidic.

The cells of people with diabetes have a hard time receiving the glucose they need for energy. This can be because there is not enough insulin in the body, insulin resistance has developed, or there is not enough sugar in the blood (hypoglycemia). This can happen if a person takes too much insulin from insulin injections or is caused by diabetes medications.

If the cells cannot access glucose, they will start to break down fat for energy. The chemicals that are made when fat is broken down are called ketones.

When ketones build up, they can poison the body. This condition is called diabetic ketoacidosis or just DKA. People with both type 1 and type 2 diabetes can go into DKA, but it's more common if someone has undiagnosed or poorly controlled diabetes.

DKA can come on slowly or quickly. Sometimes, DKA comes on in just a few hours, especially if a person is vomiting.

Early signs of DKA include:

• Thirst
• Very dry mouth
• High blood sugar levels
• High ketone levels in the urine

As DKA progresses, you may experience:

• Nausea, vomiting, or abdominal pain
• Constantly feeling tired
• Dry or flushed skin
• Breath that has a fruity odor
• Trouble breathing
• Difficulty paying attention
• Confusion

If DKA is not treated a person can go into a coma or die.

Urinary Tract Infections (UTIs)

Urinary tract infections (UTIs) happen when bacteria such as E. coli get into the kidneys, ureters, bladder, and/or the urethra.

UTIs are common, especially in those born female because they have a shorter urethral length and can have post-menopausal changes in the vagina.

UTIs often cause urine foul-smelling, but they can also cause sweet-smelling urine.

Other symptoms of UTIs include:

• Frequent and urgent need to urinate
• Pain when urinating
• Nighttime urination
• Urine leakage
• Blood in urine
• Changes in the odor of urine (especially foul-smelling)
• Cloudy urine
• Pain in the side, abdomen, lower back, penis, or pelvic area
• Pressure in the lower pelvis
• Pain during sex
• Temperature over 100 F and chills
• Fatigue
• Vomiting
• Mental changes or confusion

Foetor Hepaticus

Foetor hepaticus is the smelly breath of people with liver disease. It's also called the “breath of the dead" and happens when compounds from liver damage get into the lungs. It can also make the urine smell unusual.

Maple Syrup Urine Disease

Maple syrup urine disease (branched-chain ketoaciduria) is an inherited disorder that causes a newborn baby to be unable to process amino acids properly.

Maple syrup urine disease occurs in one in 185,000 infants worldwide. The most common and most severe form of maple syrup urine disease is the classic type. It is usually noticed shortly after birth.

Other forms of the disease can show up in later infancy and childhood. Though less severe, they still require medical attention.

The symptoms of maple syrup urine disease include:

• Sweet-smelling urine
• Poor feeding
• Vomiting
• Lack of energy (lethargy)
• Abnormal movements
• Delayed development

If maple syrup urine disease is not treated, it can cause seizures, coma, and death.

Diagnosing the Cause of Sweet-Smelling Urine

Sweet-smelling urine is always a reason to call your healthcare provider. They can do a test of your urine (urinalysis) to find out what is causing the smell. They can also do other tests, such as:

• Blood tests
• Imaging
• Genetic analysis

Treatment by Cause

The treatment for sweet-smelling urine depends on what's causing it. Each medical condition that can cause sweet-smelling urine has its own treatment protocol.

Diabetes

The best treatment for diabetes depends on the type of diabetes, but usually involves lifestyle changes like diet and physical activity.

• People with type 1 diabetes will require insulin through injection or pump.
• People with type 2 diabetes or gestational diabetes might be able to manage through lifestyle changes alone, but they may also need insulin or medications to control the condition.

Diabetic Ketoacidosis (DKA)

DKA is a medical emergency that always needs to be treated in the hospital. People with DKA need to get insulin, fluids, and other treatments to help their bodies recover.

Urinary Tract Infections (UTIs)

UTIs are treated with antibiotics. The medication you need for a UTI depends on which bacteria is causing the infection.

While they do not cure a UTI, there are also medications that can help ease UTI symptoms while you're waiting for the antibiotics to work.

Foeter Hepaticus

Foeter hepaticus is treated by addressing the damaged liver. Usually, that means figuring out what is causing the liver damage and treating that problem.

Medications and liver-friendly lifestyle changes such as a nutritious diet and avoiding alcohol are common ways to manage liver damage. However, liver damage cannot always be reversed.

Maple Syrup Urine Disease

Maple syrup urine disease cannot be cured. A person with the condition needs lifelong treatment that includes following a protein-restricted diet and taking supplements.

Metabolic crises that can result from this condition require immediate medical attention.

Preventing Sweet-Smelling Urine

To avoid having sweet-smelling urine, you'll need to prevent or treat the conditions that cause it.

Diabetes

To prevent the sweet-smelling urine associated with diabetes, blood sugar levels need to be controlled.

Type 1 diabetes is an autoimmune disorder that cannot be prevented. Most people are born with type 1 diabetes and need to take insulin throughout their life.

Type 2 diabetes comes on later in life. The symptoms and side effects of type 2 diabetes can often be prevented by making lifestyle changes or taking medication.

Diabetic Ketoacidosis (DKA)

Managing diabetes is the first step in preventing DKA. Recognizing and addressing the early warning signs of DKA is also important.

You can check your ketone levels and monitor them at home using test strips. If you get sick (such as with a cold or flu), checking your levels is very important.

If your ketone levels are high, you need to contact your provider—especially if you are also vomiting.

Avoid exercising if your ketones and blood sugar levels are high. It could be a sign that your diabetes is out of control and you need treatment.

Urinary Tract Infections (UTIs)

There are ways to prevent UTIs. There are some steps you can take, including:

• Drink plenty of fluids, particularly water, to help flush bacteria from the urinary tract
• Practice good hygiene, such as wiping from front to back, hand-washing, and changing menstrual products frequently
• Avoid fluids and foods such as alcohol, citrus juices, caffeinated drinks, and spicy foods, which can irritate the bladder
• Urinate before and after sex
• Wash the genital area with warm water before sex but do not douche
• Avoid genital deodorants
• Change birth control methods (diaphragms and/or spermicide can increase the risk of UTIs)
• Use water-based lubricant during sex
• Wear cotton underwear and avoid tight clothing
• Consider cranberry supplementation

People who get frequent UTIs are sometimes put on low-dose antibiotics to prevent infection.

Foeter Hepaticus

Taking care of your liver is the best way to prevent foeter hepaticus. Here are a few steps that could help prevent liver damage:

• Exercise regularly
• Maintain a healthy weight
• Avoid alcohol or other substances that are toxic to the liver
• Take medications only as necessary. check the side effects, and make sure they will not interact with other medications or supplements you take (even ones that are over-the-counter)
• Keep up-to-date with vaccinations
• Practice safety while traveling with regard to food, drink, and local health threats
• Make sure proper safety guidelines are followed during body modification procedures such as tattoos and piercings
• Practice safe sex for STI prevention

Maple Syrup Urine Disease

Maple syrup urine disease is a recessive genetic disorder. A person will get the condition if they receive an affected gene from both parents.

If both parents have one affected gene and one unaffected gene (carriers) their chances of having a child with the condition is 25% for each pregnancy. The chance of their child being a carrier is 50%, and the chance of their child not receiving an affected gene at all is 25%.

Genetic testing can be done on the parents before conception and/or on the zygote/embryo/fetus after conception to check for the condition.

Summary

Sweet-smelling urine can be caused by different medical conditions. It's always a reason to talk to your healthcare provider. Some conditions that cause sweet-smelling urine are easy to manage, but others can be life-threatening without immediate medical treatment.