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The human body has a robust system of warning signs and symptoms to tell us when something isn’t right. One of the key indicators is our urine. For example, the color of urine is an important marker. Dark yellow urine can be a sign of dehydration, while a pale yellow color can indicate that someone is well hydrated. What does the odor of urine tell us about health? And specifically, what does it mean if urine smells sweet? Does hypothyroidism play a part? Ahead, we answer these questions.
Urine consists primarily of water. Generally, the smell it gives off is due to the amount and concentration of waste products excreted by the kidneys. Urine with more water and less waste produces little to no odor. More concentrated urine -- seen in dehydration, for example -- produces a noticeable ammonia-like odor.
There are also certain foods, vitamins, and medications that can cause a change in the odor of urine. Asparagus, for example, is a well-known cause of strong-smelling urine due to a naturally-occurring sulfurous compound called asparagusic acid. Some vitamins and medications, such as vitamin D and B vitamins and medications for diabetes and rheumatoid arthritis, can also cause a more pungent smell.
There are also health conditions that can affect the odor of urine. For example, a urinary tract infection (UTI) or other infection is often associated with a fishy urine smell.
A sweet smell in urine can point to other health conditions. These include type 1 or 2 diabetes, diabetic ketoacidosis, bladder fistula, Maple syrup urine disease, and yeast infections.
Diabetes: Diabetes can result in hyperglycemia -- elevated blood sugar levels. When diabetic patients are undiagosed or not adequately managed, they can develop strong, sweet-smelling urine due to the accumulation of sugar and ketones.
Diabetic ketoacidosis: Diabetic ketoacidosis -- also known as DKA -- is a condition caused by a lack of insulin in the body. It is most common in people with type 1 diabetes but can also occur with type 2 diabetes. Insulin encourages the body to use blood sugar (glucose.) In uncontrolled diabetes, when there is a lack of insulin or it is not used correctly, the body will begin to break down fat instead. Don’t mistake this as a good thing, however. The breakdown of fat releases harmful, acidic substances called ketones. DKA can cause various symptoms that can be dangerous such as shortness of breath, tachycardia, dizziness, unintentional weight loss, drowsiness, and loss of consciousness. The combination of high ketones and elevated blood sugar levels in DKA is considered a health emergency that requires immediate treatment.
Gastrointestinal bladder fistula: While rare, with bladder fistula, an opening forms between the bladder and other organs or the skin. More often than not, the bladder opens to the bowel or the vagina. Fistulas to the bowel or gastrointestinal system are usually the result of an inflammatory disease like Crohn’s disease or diverticulitis. Symptoms include diarrhea and poor absorption of nutrients.
Maple syrup urine disease: An inherited disorder, people with maple syrup urine disease (MSUD) cannot properly process certain amino acids (protein building blocks). These amino acids are found in foods such as milk, meat, and eggs. This condition is usually seen soon after birth and is associated with other symptoms such as vomiting, lethargy, abnormal movements, and delayed development.
Vaginal yeast infection: A fungal yeast infection (Candida albicans) does not it itself cause urine to smell sweet. Instead, it can cause the vaginal discharge or cervical mucus to have a sweeter smell, making it seem that the urine itself smells sweet. Other symptoms include vaginal itching, burning, redness, irritation, and discharge.
The short answer is no. There’s no direct link between an underactive thyroid and sweet-smelling urine. Be aware, however, that autoimmune Hashimoto’s thyroiditis and hypothyroidism are associated with a significantly increased risk of type 1 and type 2 diabetes and a mixed autoimmune form called Latent Autoimmune Diabetes in Adults (LADA). Since sweet-smelling urine can be a symptom of diabetes, thyroid patients should periodically evaluate their blood sugar with the Hemoglobin A1C (HA1C) test and fasting plasma glucose (FPG) tests. People with Hashimoto’s or hypothyroidism should also pay attention to careful blood sugar management.
Changes in urine color and smell usually go away on their own within a day or two when the cause is food or dehydration. But when an odor persists longer, you have sweet-smelling urine, or you have any other accompanying symptoms, it’s time to seek medical attention. Key symptoms to watch for include fatigue, more frequent urination, urinary urgency, burning or pain when urinating, blood in the urine, persistent lower abdominal pain, mid or lower back pain, mental confusion, unexplained weight changes, or extreme thirst.
In addition to regular blood sugar testing, periodic thyroid testing is essential for anyone with an underactive thyroid. The Paloma Complete Thyroid Blood Test kit can make thyroid testing – and regular thyroid screening -- affordable and easy. Your convenient at-home thyroid test kit comes with everything you need to collect and mail in your sample to test TSH, free T3, free T4, and TPO antibodies, with the option to add on reverse T3 and/or vitamin D.