Orthostatic Proteinuria

What is orthostatic proteinuria?

Orthostatic proteinuria is the presence of protein in your urine (pee) when you go to the bathroom while standing up or sitting, but at a normal level when you pee after lying down on your back (supine) or sides (recumbent) for a long period. It’s a harmless type of proteinuria. Another name for orthostatic proteinuria is postural proteinuria.

Orthostatic proteinuria is a normal condition that primarily affects children and adolescents. It doesn’t mean you have any problems with your kidneys, and it won’t cause any harm. In most people who have orthostatic proteinuria, it goes away on its own without treatment.

What does protein do?

Proteins are important to your overall health. Some of their functions include:

• Creating and developing bones and muscles.
• Controlling how much fluid is in your blood.
• Fighting off infections.
• Repairing damaged tissues.

Is orthostatic proteinuria dangerous?

No, orthostatic proteinuria isn’t dangerous. Studies show that it doesn’t lead to kidney conditions, such as chronic kidney disease (CKD).

How common is orthostatic proteinuria?

Orthostatic proteinuria is rare. Approximately 2% to 5% of adolescents have orthostatic proteinuria. It’s very rare in people over 30.

What are the signs and symptoms of orthostatic proteinuria?

Orthostatic proteinuria has no obvious signs or symptoms that you can see or feel. The only way to know that you have orthostatic proteinuria is if a healthcare provider tests the protein levels in your pee.

What are the common causes of orthostatic proteinuria?

Healthcare providers and medical researchers aren’t sure what causes orthostatic proteinuria. They think it may relate to kidney (renal) conditions. These may include:

• Glomeruli abnormalities. Your glomeruli are groups of tiny blood vessels in your kidneys that help filter your blood. Some studies show that about 43% of people with orthostatic proteinuria have slightly thicker walls in their glomeruli.
• Abnormal hemodynamic response. Hemodynamics is how blood flows through your arteries and veins (blood vessels). Your renin-angiotensin-aldosterone system (RAAS) is a system of hormones, proteins, enzymes and reactions that helps control your blood flow. Issues with your RAAS may cause an abnormal response in your blood flow that affects your kidneys.
• Nutcracker syndrome (left renal vein entrapment syndrome). 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.

Some experts also think that gravity may affect your glomeruli. They suspect standing or sitting for long periods may cause your kidneys to leak protein.

Who does orthostatic proteinuria affect?

Orthostatic proteinuria mainly affects adolescents, and it’s more common in boys and children assigned male at birth (AMAB). Orthostatic proteinuria in adults is rare.

What are the complications of orthostatic proteinuria?

Healthcare providers consider orthostatic proteinuria a benign (harmless) condition. It doesn’t threaten your kidneys, overall health or life.

How is orthostatic proteinuria diagnosed?

A healthcare provider will review your medical history and conduct a physical examination. They’ll also order tests to help confirm their diagnosis.

They may also refer you to a nephrologist. A nephrologist is a medical doctor who specializes in conditions that affect your kidneys.

What tests will be done to diagnose orthostatic proteinuria?

Your healthcare provider will conduct at least two urinalyses (urine tests). During a urinalysis, you’ll pee into a special container at your healthcare provider’s office or a hospital.

During the first urine test, your provider will take a “day” sample. This is typically the first time you pee in the morning after you’ve been asleep at night on your back or sides. They’ll take a “night” sample for the second urine test. They’ll collect the second sample late in the evening, after you’ve been sitting upright or standing all day.

They can confirm orthostatic proteinuria if you have more proteins in your early morning sample than in your night sample.

How is orthostatic proteinuria treated?

Orthostatic proteinuria doesn’t require treatment. You don’t need to change your diet or stop physical activities. However, it’s a good idea to monitor your protein levels if you or your child has orthostatic proteinuria. Your healthcare provider may recommend a yearly urine test to monitor your protein levels.

Can orthostatic proteinuria be prevented?

No, you can’t prevent orthostatic proteinuria. However, it’s not a harmful condition.

What can I expect if I have orthostatic proteinuria?

The outlook for orthostatic proteinuria is excellent. It isn’t a sign of chronic kidney disease or any other kidney condition, and you don’t need any treatment.

How long does orthostatic proteinuria last?

Orthostatic proteinuria usually goes away on its own as you get older.

When should I see my healthcare provider?

You don’t need any treatment for orthostatic proteinuria. In some cases, your healthcare provider may recommend a yearly urinalysis to monitor your protein levels.

What questions should I ask my healthcare provider?

• How do you know I have orthostatic proteinuria?
• Do you recommend yearly urine tests?
• Should I see a nephrologist?

A note from Cleveland Clinic

Orthostatic proteinuria is a harmless type of proteinuria that healthcare providers typically see in children and adolescents. It just means you have higher protein levels in your pee when you stand up than when you sit or lie down. It doesn’t mean you have any issues with your kidneys, and it usually goes away as you get older. If you or your child has orthostatic proteinuria, ask your healthcare provider if they think you need annual follow-ups.