Proteinuria is a condition that indicates the presence of high levels of protein in your urine. There are several types of proteinuria, and one is called orthostatic proteinuria. This blog post will highlight everything you need to know about orthostatic proteinuria, including:
- Definition of orthostatic proteinuria
- Causes of orthostatic proteinuria
- Mechanism of orthostatic proteinuria
- Diagnosis of orthostatic proteinuria
- Management and monitoring
- When to seek medical advice
- Taking a proactive approach to your kidney health
If your doctor or nephrologist informs you that you have orthostatic proteinuria, you should not panic. We hope this FKP Kidney Health blog gives you the reassurance you need surrounding this specific type of proteinuria.
Introduction
Proteinuria, a medical condition marked by elevated levels of protein in your urine, can be classified as transient, orthostatic, or persistent. Transient proteinuria is widely regarded as harmless because the underlying issue causing this type of proteinuria (a kidney stone, for example) usually resolves on its own. Persistent proteinuria, on the other hand, is rather serious because it implies that the underlying condition is pathological in nature—patients with this type of proteinuria may be diagnosed with chronic kidney disease, lupus, or hypertension, just to name a few.
Orthostatic proteinuria, also known as postural proteinuria, is similar to transient proteinuria because its course is self-limiting. Of all the classifications of proteinuria, orthostatic proteinuria evades doctors and researchers. Orthostatic proteinuria primarily manifests when an individual is in an upright position, but the exact causes of orthostatic proteinuria remain unknown.
Understanding Orthostatic Proteinuria
According to an article titled “Orthostatic Proteinuria” published by the National Library of Medicine, orthostatic proteinuria is defined as “a condition where an abnormally large amount of protein is excreted in the urine when the patient is in an upright position and normal protein excretion in the supine position. It affects approximately 2 to 5% of adolescents and is uncommon after 30 years of age.”
Orthostatic proteinuria appears when a person is standing, sitting, walking, or performing other common physical movements. Excess protein does not appear in urine while that person is lying down or sleeping. A majority of adolescents and young adults find that their diagnosis of orthostatic proteinuria resolves on its own by the time they reach adulthood.
Orthostatic proteinuria is a benign condition, which means that it does not pose a threat to your health. The aforementioned article notes that a proper diagnosis of orthostatic proteinuria is important within clinical practice because if you have this type of proteinuria, your doctor should not perform a kidney biopsy or ask that you undergo further testing. That would be unnecessary.
If you or your child have been diagnosed with orthostatic proteinuria, it will be noted in your medical chart, but in most cases, no further action or specific treatment is required beyond regular monitoring of your kidney function.
Causes and Mechanism
The underlying causes of orthostatic proteinuria and the mechanism behind this type of proteinuria include:
- Postural Changes: Orthostatic proteinuria is also known as postural proteinuria because your body position seems to influence how the glomeruli (the tiny blood vessels in your kidneys) filter your blood. Cleveland Clinic notes the following: “Healthcare providers and medical researchers think that when you’re in an upright position, pressure on your left renal vein causes more protein to flow through your glomeruli than when you’re lying down.” When you’re sitting in an upright position, the change in blood flow to your kidneys may make the kidney’s filtration units more permeable. It’s also possible that standing or sitting for long periods is responsible for the excess protein leakage.
- Kidney Function: The aforementioned Cleveland Clinic article further states, “Some studies show that about 43% of people with orthostatic proteinuria have slightly thicker walls in their glomeruli.” Even if the walls of your glomeruli are thicker, you can most likely still rest easy knowing that your kidneys are functioning well outside of this issue. Again, since orthostatic proteinuria is benign, this condition does not indicate that you have kidney damage. It simply means that your care team has noted that protein leaks into your urine when you are in an upright position.
Diagnosis of Orthostatic Proteinuria
There are two specific ways that orthostatic proteinuria is diagnosed:
- 24-Hour Urine Collection: In order for your doctor to accurately diagnose orthostatic proteinuria, you will need to collect and provide urine samples over a 24-hour period. Those urine samples will be analyzed to determine if protein excretion increases during the day, which means that your frequent changes in position are indeed contributing to the presence of protein in your urine.
- Supine and Upright Testing: Supine and upright testing involves your doctor comparing the protein levels of urine samples given when you are lying down and when you are upright. Making these distinct comparisons helps your doctor determine if the proteins leaking into your urine match the positions you’re in—this is to say that when you’re lying down, you should not have protein in your urine, but when you’re upright, protein in your urine is to be expected.
Undergoing these tests is crucial so your doctor can be sure that you have orthostatic proteinuria. This will, in turn, rule out pathologic proteinuria, the far more concerning type of proteinuria that indicates a serious underlying medical condition.
Management and Monitoring
After a confident diagnosis of orthostatic proteinuria has been made, you and your doctor should discuss management and monitoring as it relates to orthostatic proteinuria.
Your doctor, first and foremost, should reassure you that orthostatic proteinuria is generally harmless. Treatment is usually not necessary and, best of all, this type of proteinuria is known to resolve on its own over time.
Even though orthostatic proteinuria is not a major cause for concern, you should still see your doctor regularly. Your doctor will continue to monitor your kidney health and proteinuria levels. Follow-up appointments also allow you to discuss any concerns and/or ask any questions you may have as well as make your doctor aware of any recent changes in your health.
We’d also like to note that when it comes to your kidneys, staying hydrated and maintaining a healthy lifestyle can support how these delicate yet powerful organs in your body function. We encourage you to do everything you can to keep your kidneys healthy.
When to Seek Medical Advice
Orthostatic proteinuria is typically benign, but you should consult your doctor if you are worried that you are experiencing unusual symptoms related to your kidney function. Symptoms such as swelling, foamy urine, increased urination, and high blood pressure readings should be promptly evaluated. Your doctor can conduct further diagnostic testing to determine if any underlying conditions are present.
Taking a proactive approach to your kidney health means maintaining open communication with your healthcare provider year-round and making healthy lifestyle choices so your kidneys can function at their best.
Empowering Patients with Knowledge
Thank you for visiting the FKP Kidney Health blog to learn more about orthostatic proteinuria and how it differs from the other two types. In this blog post, we addressed what orthostatic proteinuria is, the causes of orthostatic proteinuria, and why it’s typically not concerning, plus how it’s diagnosed, managed, and monitored.
Again, if you have been diagnosed with orthostatic proteinuria, rest assured that it’s a benign type of proteinuria that’s common in individuals younger than 30. Relatively simple urine tests will be necessary to accurately diagnose this type of proteinuria; your doctor must classify what type of proteinuria you have. If indeed it is orthostatic, you will not be asked to take any further action because orthostatic proteinuria usually goes away on its own.
Stay tuned for our next blog post in our proteinuria series. We are committed to providing you with comprehensive information so you can make well-informed decisions about your kidney health.